I like the pokestops idea a lot - maybe every 100th stop will give you raid class rewards as if you just defeated a level 2 or 3 raid. The problem I suppose would be rural areas without pokestops in abundance. I am quite lucky in that way. I have pokestops. In a rural area with one stop you would have to be at a stop for over 8 hours spinning every 5 mins. Whereas in an area with 20 pokestops in a 5 minute circuit you could be done in 25 mins.
Still a cool idea, but does worsen urban : rural gameplay standards.