Why not play both?

From what I saw on PTS, those options are gone. I had them set on a character created prior to the addition of 1.2 and managed to copy over the bars with the rest of the UI on a newer character. But when I went to activate the bars on the new character, I couldn't find them. To the OP, if you have a PC that has the bars set, save the UI for that character, then import that UI to whatever character you want the bars on. It does work cross-faction, as I had the bars on a SW and imported them to a JK.

Merc comms went away in 1.2. You used to get 1 item with 200 Merc and 200 WZ, but that has changed. I don't recall what the costs are now.

You aren't missing anything. You can filter for light/medium/heavy and level range, but not body slot. This is a common complaint. This would be nice, but as far as I know, it doesn't currently exist. To each their own. I play a healer and don't have a problem switching from group mates to enemies. Then again, I play purely heal-specced. If you are built to both DPS and heal, I can see where this could be tricky.

I started in Early Release and my highest level is 37. Of course, I also have a 30, 26, 7, and 6. No, I am not an alt-aholic. Why do you ask?

Nope. The class creation page is (to be blunt) kind of wrong. You can get off the starting planets as early as (I have heard) LVL 7. However, if you actually do the side quests, 11 or 12 is more likely. If you pick your AC at a higher level, you will still get all the skill points you have earned. (So if you pick it at LVL 11, you'll have 2 skill points to allocate, rather than just the 1 you would have gotten at 10.) They may have decided in their heads what AC they would take, but you cannot actually select your AC until you get to the Fleet. I only play a Powertech, so will leave the Merc discussion for someone else. As a Powertech player who has not yet reached LVL 50, I can say I've never had a problem with playing a Powertech. That said, however, I am in a very laid back guild that doesn't really care what class you play, so long as all the roles are covered and you have a decent idea of how to play your class. Warzones are randomly assigned teams, so there isn't an issue of the Ops leader refusing to take Powertechs and taking Juggernauts instead. I see plenty of Powertechs (and the Republic equivalent) in WZs.

Go back to where you arrived at the Fleet. You will see an NPC there with a quest triangle over their head. Talk to that person to get the quest. The only person who can answer that question is you. Do you want to Tank? If so, Powertech. If you want to DPS, Mercenary. (Powertech also has a DPS tree, if you want to be able to switch between Tank and DPS, but there is a cost in that.)

Pull up the map and you'll see a section labeled as Galactic Market. I believe it's the bottom left on the Imperial Fleet. Not sure about the Republic Fleet.

I would take a look at how you are getting and spending credits. You said you have 84K at LVL 38. My LVL 37 has 225K. Are you buying a lot from the GTN? Are you sending your companions out on a lot of mission? If you have a crafting skill, are you selling what you make on the GTN? Are you picking up all the trash drops and selling them to vendors? Also, if your repair bills are that high, you may be questing too much over your level. If that is the case, do some space combat, PvP, or something to get your levels up. You'll die a lot less, which will really decrease your repair bills.

If you have an iPhone or (I think) an Android, it is a free app. I debated getting it for my phone, but decided the cost ($0 ) is worth the security. I find it is easier to decide on your path early on, but that does not mean you have to select only your chosen path. (My extremely-Light Sage has a few Dark choices.) There are benefits to getting to Light or Dark V, but you can get there, even if you select choices for the other side. If you want to play Neutral, it is a lot easier to decide that early on so you can balance your choices. (Neutral is 1000 to -1000, so there is some flexibility. My "Neutral" Powertech tends to stay about -400.)

As you get points, your Light (or Dark) level increases. You can see your current level by pulling up your character (default key: C). On the left side of the image of your character, you'll see a curved bar that goes from blue, to gray, to red. Scroll over the marker on the bar and you'll see: (1) your current Light points, (2) your current Dark points, (3) your overall Light/Dark Points (Total = Light - Dark), (4) your Light / Dark level, and (5) the total points required for the next Light / Dark level. Some gear has a requirements for a certain Light / Dark level. Once 1.2 comes out, you will unlock certain abilities for all your toons on a server if you have a LVL 50 with Light V, Dark V, or Neutral. As you level Dark, if you have Sith corruption turned on in Preferences, the appearance of your toon will chance. (Skin gets paler, skin looks cracked.)

Biochem makes medpacks that heal the player and the companion. Check the GTN.

Valor has nothing to do with Light/Dark side. Valor is a measure of your PvP level. You get it by participating in Warzones and open world PvP.

For the most part, this advice is very good. I only want to make a few comments... I have a slightly different perspective. If you find an orange lightsaber at a vendor with better mods, you might be ahead to buy it. It works out the same as upgrading the mods, and you get multiple upgrades at once. This will also allow you to save your Commendations to upgrade other things. (Once you start getting a lot of orange gear on yourself and your companions, it takes a lot of Commendations to keep everything upgraded.) This is true. However, you may want to consider ripping out Enhancements, especially if you got a new companion and are working to outfit them in oranges. (Mods and Armoring also, if they are updated enough and your companion uses the same stats as you.) They are Bound, but you can still put them in your companion's gear.

No, warzones are on PvE servers. You queue up for them by clicking the Republic/Imperial symbol on the lower right of your mini-map.

You have to get the mission from the person right after you arrive at the Imperial Fleet. If you are LVL 10, your class quest may not have sent you to the fleet yet. If not, just keep going through your class quest and the rest of Hutta. Even if you level up a few more times, you won't lose your skill points.

It depends on the guild. Some guilds are end-game only. Some guilds take all levels. This can be especially helpful if you are interested in HEROICS or Flashpoints, as being in a guild makes it a lot easier to find people to help you run them. Short answer... If you want a guild that will help you while leveling, they exist. If you need help finding one, let us know what server you are on and someone can probably point you in the right direction.

No. There is a 1.5(?) second delay between when you activate a power and when you can activate another.

If I understand you, you can't. You can't activate another power until the Global Cooldown wears off.

Yes. In order to start getting the top tier PvP gear, you need to be LVL 50 and Valor 60. (I think it is 60.) After that, better and better PvP gear requires higher Valor. (Max Valor is 100.) As I understand it, the PvP gear is good for PvP, as it decreases damage taken from other players and increases damage you do to other players. However, it does not affect PvE. So if you really aren't interested in LVL 50 PvP, there is no requirement to get that gear. You can still get good gear through Ops and Hard Mode Raids. However, if you want to PvP, it's good to have.

I think what the OP meant was the only orange lightsaber they have seen is the one you are referring to. My guess is the OP sold that lightsaber for some reason.

On the bottom left corner of the vendor window is a button that says "repair all." Click it and it will repair your weapon and any damaged armor.

Although blues do sell better than greens, how well greens sell is based on the market. On my server, there are often very few item mods on the Imperial side. More than once, I've looked with my Sniper and found only mods with Strength, or Willpower. (And even then, only 3 or 4 of the right level.) I would have HAPPILY bought a green if it had Cunning, but that wasn't an option. Also, if you are selling mods for low level PCs, you may find greens sell better than blue or purple, simply because low-level PCs don't have the disposable income to buy the best, so they buy what they can afford (greens).

I play on a PvE server, so maybe it is different on a PvP server. That said... Not all areas of Nar Shadaa or Tattooine are mixed faction. (There are only certain areas that are.) I've only seen 1 person from the other faction in the mixed area of Tattooine, and I was actively looking. (Not to PvP. Just because I was curious.) I also went to the open PvP area of Tatooine and saw no one from the other faction.

Check your class forums. I haven't looked at all of them, but he ones I have looked at have multiple threads about how to PvP.