With regard the scooter - I don't think I know of anywhere I could fly below 50ft and get over trees, buildings etc. My area of operations would be pretty cinfined.
After all the time and effort required to build it it would rapidly become a white elephant.
With regard the tripod thingy - I don't think I've ever managed a complete full stopped auto - always have a bit of run-on. So if you repeat that in the whirling tripod you'd end your days very quickly! - probably with a part of a tripod up some orifice.
I spent lots of time comparing buying or building and ended up buying.
if you're interested in my prattlings have a look at
http://helipics.homestead.com
and go to [technical stuff] -> [Buy or Build]