The cartel weapons in my experience all have slots for upgrading them. (Slot for hilts, barrels, mods, enhancements, color crystals, etc) Most adaptive armor also has it i think. Should be able to add the upgrades as needed while leveling. They have basic mod vendors in the fleet and also a lot of upgrades people are selling on the GTN. My Sorcerer has a weapon from the store that was upgraded as i leveled so don't see a problem as long as they have the slots for it. You can preview them also to check before you buy. If it has the upgrade slots you can, if not then no. Hope it helps.

Not a trooper, but if you look at the quest info up on the upper right hand corner of your screen it may have a box next to the quest info, which may what you need to hit. Have had the same thing happen to me where i can't figure it out, and suddenly see the box there i'd totally ignored and that was it. (May not be, but all i can think of atm)

1) I've been using the seer tree pretty much exclusively on my sage, and haven't had too many significant problems so far. I DID do the more force power points which is smart for any build you'd do imho. Maybe not as efficient as other builds, but it works for me. (Level 46.5 atm) 2) As for my companions, i used Qyzen pretty much till i got Nadia and have been using her ever since except when one of the other companions would be a better choice for a fight. I've found that with my build, as long as i get agro on myself and keep myself healed, i can take out some of the harder mobs fairly easy. (Did that with Stark, Got myself agro and Nadia whittled him down) 3) As for the saber attacks, i still keep them up just in case. Been a few times on a long fight where a couple of whacks with the saber would have enabled me to win. Granted, it's very rare that happens, but it's still DPS so unless you need the room why not keep them up? Just my .02

Finding it fairly easy to solo stuff on my pyro PT also. Am on Belsaavis(?) atm and just hit lvl40. (Started there about 38). I've found i can solo elite stuff that has about 20-30k health fairly well so far with Mako healing me. That probably will change but having fun so not too worried about it. As for which to play, i always go by what others have said. Just play the one you like and have fun with and don't worry if it might be useful end game. What's not good now can be overpowered a few months down the line with patches and such. (Then again it may not but who knows?)

Because a beast tamer class wouldn't really fit in i'd think. Now, a class where you have a droid/robot that fights with you and levels/upgrades as you do would be interesting imho.