1,3, and 4 is still stale content. Why would I be happy about doing the same content again just because I can do it the entire way through again?
4 is the same thing as offering boosts for cash but using gold instead of cash. It still has all of the "band aid" fixes that you just got done claiming boosting for cash contains. That seems to indicate that your really motive here is all about real money transactions. And the rest is all being invented as reasons to justify why real money transactions are bad.
As a boost for gold carries all the same advantages and disadvantages as one for cash. That is because it is the same exact boost. You can't argue one is bad while at the same time saying the other is a fine alternative.
There are more that I can't think of. I'm not a professional developer at Blizzard, I'm sure they can think of something better. Whatever they come up with, it's better than paying real-life money for this shortcoming.
Having a new 90 on a new server effects the meta the same as having a new 90 on a new server. A server change ensures that there is one new 90 on that server. Competing for all the nodes, drops, raid spots etc that a boosted 90 would. It also doesn't require you to level up a character on a new server, just like boosting does.Once again I'll say it: You're creating something out of nothing. A server or faction change is not in the same line. A server or faction change is still meta-game in the sense that servers are part of the meta-game. Paying for a level 90 character is not meta, it directly effects the actual game.