Missing out on huge chunks of this game and it's ruining it for me. XP toggle please!

Pretty much every MMO is linear, sure i can get to another zone in wow but the quest giver still has a grey quest that i can't take because i'm not high enough level. Same with EQ, DCU, LOTRO. etc, etc, etc

Name them.

The OP stated that he wanted to maintain challenge, which I don' disagree with.

OP, I understand that you play for the quests, so I can only assume that you are into story. As such, I'd suggest skipping everything except for class missions on certain planets. To experience all of the story, you'll need to play through each side 4 times. If you do every single quest, every single time, you're very likely to get tired off all of the side missions very quickly.

World of Warcraft.

On my toons I've never really encountered this problem. I do all the quests on planets and I usually stay on level or am 1 or 2 levels ahead (or one level behind in my sniper's case). Guess the only way for you to really experience those quests would be to roll an alt and try to manage how many quests you do.

I'm sorry, but I believe your prediction is inaccurate and untrue. I point to all the other MMOs that offer an XP-toggle feature, which have plenty of players with plenty of alts running around as proof. If you have compelling classes, gameplay, and (in Bioware's case) storylines, people will make alts regardless of your concern.

I underlined why you are not experiencing this problem. You are skipping quests.

name them

Turning off xp gains would ruin pvp. As it is, level 10s can dominate pvp because of how the rank up to 49 is calculated. A level 10 in full blues can get upwards of 70% damage reduction and ridiculously high dmg output. The only thing keeping people from twinking in pvp is forced xp gains.

I agree. I don't play excessively (maybe 2 hours a day, if that--and I don't play every single day). I don't play the grind and kill kill kill for xp (though it seems individual kills don't net much xp thankfully). I don't pvp (though I often end up on pvp servers due to friends' preferences) so have yet to enter any wz or hutball.

Yet it's very easy, after doing class quests on a planet, one or two side quests and a couple flashpoints, to end up with a slew of greyed out quests on that planet. Sure, I could still do the quests for rp purposes, items to sell, etc., but the fact that the quests grey so quickly with very little effort on my part suggests the leveling is a bit to fast.

I wouldn't want them to make a change to the overall mechanic, thus messing things up for people who want to get to 50 as fast as possible, but the ability to toggle off xp would be great.

Edit: OP, have you submitted this to the Suggestion Box? http://www.swtor.com/community/forumdisplay.php?f=349