Your VIP color will stay
Frothing an interesting piece of trivia, when we ran MCAdmin (a very long time ago) we had a builder rank then, and it worked very well. When we switched back to hMod we could not have the rank due to software limitations.
There is one very simple reason why creative is 'elitist', that is because not everyone can build nice things, much more than that some people decide to grief others things. If people do not apply to become builders then they can still build in any of our other worlds (we have 4 others for them where they can build anywhere they like). Also here is the other added benefit of the builder rank, a user comes to our server and decides he wants to play Creative, he cannot until he has built something nice in our legit worlds. Hopefully this will make him value the materials he will be using to build with rather than just see them as instantly available as and when they need it. It need not take them long to collect materials - just look at the epic things wombatus has built in dirt! Either way I feel it is really important that new users are exposed to this side of our community, Creative doesn't necessarily fit into our ethos but we thought it would be something amazing for our users to have.
As for having a 1kx1k area where people can build, we could do that, but people get very frustrated when their structures are wiped before they are finished. Furthermore, it takes up even more moderation time.
Just give the setup we have now a chance and see if it works, we're expecting that we may have to make changes: this is inevitable.
I should also add perhaps the most elitist part of this server is VIP+ users donate for little more than a different colour name. At least with the builder rank anyone can apply to build with no obligation to donate.