If you decide to do this I'd recommend starting at something like a YMCA. The one my dojo started at already had a mat space, and the rent was very reasonable.
I know a few other Yudansha that may come over quickly
Don't make any plans based on what others say they might do, expect to be the one and only person doing everything. If help comes along you'll be happy about it rather than disappointed by those that don't follow up on what they say, and you'll already have a plan for dealing with things yourself.
I think wanting a place to train the way you want is a good reason to start a dojo. Even better would be finding a dojo that's open to letting you explore your aikido with other like-minded students. You'll probably find in opening a school, especially one of limited hours, that you're spending more time teaching basics to new students than getting your own applied aikido training in.