Yes, most of the hard mode flash points will require that you completed the normal mode version first. Some, however don't. Off the top of my head, Battle of Illum, False Emperor and Kaon Under Siege don't require it.

Since you didn't say anything about trying to use your quick travel button, I'd try that. But other than that, your best bet is to re-log so it'll spawn you outside of the instance. If none of that works, your only chance is to have CS help you out, though I'm not sure if they can.

While you can still fight effectively as a gunslinger without using cover, you're probably going to be doing about 20% less damage in a normal pve fight. What you need to do is to get into cover, blow off your charged burst, do quick shot, throw your charge, aim shot, do something else (any 1.5 sec ability), then quick shot again. Get out of cover, re-enter cover and do something similar. As a Sharp Shooter, you get so many buffs from being behind cover, that it's not really worth it to not use it. You get damage reduction which helps healers, you get extra energy which is invaluable, you get the instant charged burst, you can't use aimed shot without it, and when you exit cover, you get increased damage reduction. Basically, for a sharp shooter, you will have to use cover. For saboteur, which is a ton of fun, but hard to use in pve due to it being aoe heavy, you don't have as much abilities that require being behind cover and you can usually dot up entire groups of enemies and burn them down. I haven't tried scrapper, but from what I understand, it's mostly about staying close to your mobs and using your physical attacks. If you don't like the cover mechanic in other words, you'd probably be better off playing as a trooper. But barring that, a saboteur is a good replacement.

The bonus boss on Kaon Under Siege is really not that difficult once you figure out how to beat him and if you have two party members that can stun droids. I don't want to steal the joy of learning this on your own but if you're having trouble with the bonus boss, follow this strategy. First, if you don't have two people that can cc droids, you'll be having some trouble. The first thing you do is clear out the room right before the bonus boss. The room that has the flaming fountain in it. Then, you keep your two dps (the ones that can cc droids) near the exit door of this room and have your healer and tank pull the boss through the hallway and into the room. The tank should LOS the boss with one of the pillars to bring the boss all the way into the room. When the boss spawns the adds, they will spawn where the boss was before, in the next area and will spend time making their way to the group. As the adds enter the room, have your dps CC two of the adds and burn the third down. The group can then deal with the adds one at a time fairly easily. The second time the adds spawn, you can just kill one of the adds and keep the other two CCed and burn the boss down. Of course, you'll have to kill the adds after the boss is dead, but by that point you would have looted the boss and distributed loot, so it's all good. I hope this little strategy helps. It makes the fight a bit simpler and less hectic but it still doesn't trivialize the fight, so make sure your tank and healer can handle all the damage that the boss puts out.

On my server, Colonel Tobin. There are a grand total of 6 imperial players that are level 50. I play as republic and we have about 15 level 50 players within my guild, not all of which are on at the same time. None of us have been able to get into a WZ since the patch. We were only able to play a few matches of Huttball last night because we had enough people on in the guild that we can play against each other. Now, we could be content with that, but it's not fun to pvp against your guild mates, it harbors resentment and feuds within the guild. And before anyone says anything, no, this isn't hyperbole, this is actually happening on this server, people are actually going 15 hours in queue without a single match and then quitting for the night, waking up and queuing again for another 15 hours without a match. This is on a standard pop server. The problem is that the restriction that level 50 players face off against other players of level 50 is too much. There's little difference between facing a player that is level 49 and one that is 50 when you're level 15. The bracket should be 40-50 at least. It's a very simple fix and one that won't break the current system. It's the least bioware can do if they're not going to implement cross server pvp.