You could even make it specific to each company. If x of everyone is in, but y of my company aren't, I'm out...
But whatever the mechanism there's more than enough programmers who ought to be motivated to do this.
unionkickstarter.com is available!
Not according to international trademark law.
Do you suspect this would fall under trademark confusion? It's definitely towing a line but I don't think it's necessarily that clear-cut. It's not like they own the term 'kick starter,' they just used it in their trademarked brand.