I have r-1ed it quite a few times, it is a super fun raft run for an experienced boater.
My recommended levels are from 250 to 500ish, the biggest problem above that is fitting under the bridges especially the one above the dream house.
I have always portaged 1st falls and the top of super max, everything else goes.
The areas to watch out for is the boogie water, it is always going and there is always wood.
My consistent problem area is the section just below four falls, the moves are not super hard but tight.
I would think an r3 but would be fine in a 12' possibly an r4 but you are adding weight which changes your set up time and in some places you do not have that kind of time.
As far as put in goes, it has been awhile since I have run it and always used the old put in on then ranchers access road below the culvert bridge. I never really looked at that bridge to see if I could fit, but am doubtful a raft would fit through.
Let me know if you have other questions, as it is super fun rafting.
Danger, screw that dam drop on LSB my neck hurts just thinking about it. Let's paddle soon, we will be in the valley over the 4th.