You should be fine - I think its a better stretch for a novice than Pumphouse to State bridge. Launching at Rauncho del Rio will get you a few more rapids above SB. There'll be lots of smaller rapids down to about Bond then the river's pretty flat but has swiftly-flowing current all the way to Catamount. If you can find a campsite, camp below Bond if you can, it seems like a lot of train traffic leaves the river there.
PM me wiith your email addy and I'll send you a PDF of the BLM guidebook on the Upper C.
Nothing in the world is more yielding and gentle than water. Yet it has no equal for conquering the resistant and tough. The flexible can overcome the unbending; the soft can overcome the hard. - Lao Tse