It sounds like you don't really want to start your own guild, you're only thinking about doing it because you think you're missing out on something. Really, you aren't.

You might make a couple thousand a week in gold from maxing all the guild perks, which as a multiboxer, you won't possibly be able to unless you are a max level guild {guild XP converted to gold for challenges} run at least 8 toons{?} and have a lot of time to play each week. You'll make more in less time just doing dailies *5.

Shared banking is nice, but it's just as easy to trade or use instant mail. If you just want more storage, you can just use alts to create a new guilds as needed.