I live in absolutely the wrong place to give you advice about reasonable roads for cycling in Alaska - but you might want to check in with some of the (sort of) local bike shops. It's possible that they either know of or sponsor rides, or can provide information on the roads in your area.
I just did a search in Google and came up with a possible source of information - and that is the Arctic Bicycle Club which is based in Anchorage. It's likely that their rides are in the Anchorage area as opposed to close to your home, but it's possible that there are club members who have ridden in your area and can give you some tips.
Tour buses and motor homes are not the best vehicles to share the road with - although in my experience the buses are usually OK. The motor homes can be scary because the drivers aren't always as skilled as they should be. But my advice if you're sharing the road with them it to make sure you are far enough out into the driving lane that the drivers understand that they need to pull out to pass you.
--- Denise