[RPG] Should I take a side in an external player conflict, or let the game die

The real question is how high of a priority for you is playing a tabletop RPG?

There's no right answer except your own.

If getting together with buddies (over Skype or face-to-face) to roleplay for a couple hours a week is really a high priority for you, you'll make time to do it. If your work/hobbies/etc get in the way of that time, then that tells you where your priorities lie... and there's nothing wrong with that.

One of the guys in my group is invovled with a community drama group. Of the 8 people in my group, he misses the most sessions because his acting is more important to him. Another guy has been playing D&D in some form or another for 20 years and never misses a week simply because he reschedules his other commitments around gaming night because he really wants to be there.

I think the real answer here is to sort out what is important to you and allocate your time accordingly.

Personally,

• My work friends know that I'm not available on Thursdays to hang out because I'm playing D&D.
• My wife knows that I will be gone from 4:30-8:30 every Thursday, so she and my son either make plans for a playdate or go spend time with Grandma, etc.
• When I started my new job I made the decision to get up early every day and work 7-4 to get out in time for gaming.

Obviously life tries to get in the way plenty of times. It's just a matter of whether you let it or not.

You're not having fun.

Since the entire point of role-playing is to have fun, you need to do something about it. In particular, it sounds like the character he's playing (called a GMPC) is seriously distracting him from his GM task of running a fun story for the other players at the table.

You have several options, depending on whether you're willing to accept him as a GM as long as he changes, or if you can accept him as a part of the group as long as he isn't GMing:

1. Talk to the GM about his behavior. Try to be non-confrontational, and don't have this conversation in front of the group; that will just make him defensive and won't accomplish anything. Try persuading him to not bring a character along with the group; he's GMing, not playing.
2. Sit out the current game, until the GM is done. There's no need for you to continue playing a game you dislike, so take a break until he's done running the game. Then join the next game, that someone else in the group will run.
3. Take over GMing duties, with the support of the rest of the group. Since they already asked you to be the GM, they'll almost certainly be willing to let you run the game. Talk to the other players about this individually before you try this; if you have enough support, you'll be able to usurp his position as GM, and start an entirely different game. Perhaps the current GM will be a better player than they are a GM. And look on the bright side: you now have some fantastic examples of how not to GM, which will make you much better at this new role! You can also combine this with #2 above: sit out the game until it's over, then be the next GM. (Warning: given what you've described of his personality, the current GM is unlikely to take this well.)
4. Start a separate gaming group, inviting whoever is willing to play without the problem GM. If some people are unwilling to play with the new group because they don't want to exclude the current GM, then you'll need to exclude them as well. Recruit a few other players from elsewhere if you need to.
5. Find a new gaming group. If all else fails, just don't play with this group at all. If they're willing to play with someone they dislike, and you can't persuade them to kick out a problem GM, that's their problem. It doesn't have to be your problem.

Note that none of these options include playing a game you dislike with a GM who you hate. He isn't going to improve on his own, unless you talk him into changing or encourage the group to leave him behind.

On a slight tangent, see the Geek Social Fallacies. It sounds like some of the members of the gaming group are suffering from GSF #1: "Don't exclude anyone" and GSF #5: "Failing to invite someone is a deliberate snub."