Sorry, I don't know.

It is a long hike with many switchbacks.

Yes. There are benches near the trail start and across the street from the nature center.

Yeah, it should be fine for the RV's. There's plenty of room on the road for two big vehicles and parking at a few different areas.

There are lots of trails around Golden. I would recommend going up to Castle Rock rather than Chimney Gulch (up Lookout Mtn) or Apex. It is a much shorter hike (about 200 m vertical and perhaps 30 minutes up), but it is all open and at the top you will be poised above downtown Golden. Search for the Lubahn Trail.

A would allow a couple hours

I took the pic from near the top of Lookout mountain in Golden CO. Just a short drive outside of Denver. I took the pic with my IPhone 6.

The road to Lookout Mountain is open 24/7 just like any other road in the city. It is not a park. There is no fee. It is just a pull off like an observation point. The road is steep and curvy but they do keep it maintained. I am not clear what store the other writer is referring to. I am not aware of any "Lookout Mountain" store. There is a museum and a park and a few other things up at the top...Buffalo Bills grave, etc. Those operate using normal business hours - check their website before going to make sure they are open.

Generally, there is good cell service; sometimes it's spotty, like in any hilly and mountainous area.

The ride up the mountain starting at 19th St in Golden is free. Visit Buffalo Bill's grave (great views) when you reach the top on the right. Paul