I do all those every summer. I would stay away from Imogene and Mineral Creek (lower end of Engineer Pass next to highway 550) without a modest lift. Instead of Imogene, take Ophir Pass. A way back to the east side would be Last Dollar Road which is very easy.

Despite what others have posted, Black Bear is not for the faint of heart. Poughkeepsie is definitely out. Both are off limits if you rent a Jeep locally.

Instead of Mineral Creek, take California, Hurricane, and Corkscrew.

Another good drive is Clear Lake out of Silverton. This is a bit challenging but doable in a stock 4Runner.

And be sure to take the road to the top of the falls in Telluride where the first A/C power generating station was built by George Westinghouse to light the mines.