Ok, since you all ignored me I went out and answered all my questions in a scouting / biking / rafting mission. Here is everything I know / ran / saw / found out about water around Chitina. Strong disclaimer in that my reporting is based on fairly moderate water levels that I observed (Copper at 14ft for comparison):
Kuskulana - Ran from bridge to Chitina (continuing on Chitina). Embick reported as III-, I concur. At moderate water level run, not overly technical but required non-stop attention due to speed, turbulence, eddy lines, and not being able to see rocks / shallow spots ready to throw off your balance. Closer to ‘civilization’ with possible outs I might even call it a II. Would not want to see this at high water with many spots of water trying to push the canyon walls out of the way instead of turning gently. http://www.youtube.com/watch?v=VDPkHKMICQU for a short video. Makes an excellent bike / raft trip from Chitina. I left my bike at the bridge for fear of the unknown, but at these levels an attached bike and/or open packraft would be fine as the “playspots” are aviodable. I’ll provide additional info to any one interested as I thought this made for an awesome remote mini-trip.
Kuskulana, upper reaches - Scouted from Nugget trail. Embick reported as V-, I observed IV from first possible put-in. Might make a good run at low-water, probably sans bike. Hazards would be the unknown in the canyon, swift current, and no possible exit until bridge. FYI Nugget trail makes for excellent biking.
Strelna - Too small to run
O’Brien - Observed as unrunnable (well, at least you wouldn’t be doing it more than once)
Kotsina - Embick reported as unrunnable except for a short 12 mile section at the upper reaches before canyon. Access for this would probably be more work than its worth.
Chitina - Ran from Kuskulana to Copper confluence as part of Kuskulana run. Commonly reported as II. At ideal conditions I concur. Hazards include have-to-see-to believe eddy lines, strong current (was doing up to 10mph in a packraft), turbulence, the 2% of the 2-3 foot wave trains that weren’t nice and gentle, and the very real possibility of notoriously (per locals and observed) hideous winds near the Copper confluence. I experienced a short taste of all of the above at once which turned this quickly away from a sit back and relax picture taking time to a few moments of using all my wits and muscles (what there are) to keep the raft upright. I would be especially cognizant of wind conditions on this section, perhaps timing things to hit it early in the day when hopefully the winds haven’t kicked up too bad yet. Fortunately the winds would normally push you towards the road side, not that that bushwhack would be easy but doable in emergency.
Copper from Chitina confluence to Urantina - Observed by biking abandoned railbed alongside. Jettmar reported as II, I concur. Hazards would include probable headwinds, powerboats, and limited egress and stopping points. FYI the railbed makes for excellent biking.
Klutina - Embick reported as III, I concur. Run by commercial trips. This looks like some powerful fun, lighting quick non-stop action, at least on the lower sections observed. Hazards include quick current ie flip out of packraft might not see it again, powerboats, and gauntlet of fishing at bridge. Access might be an issue, native lands (I’m not sure where commercial guides put in and whether they have/need permit). Imagine ok if start at lake. I don’t think I’d personally try with a bike attached.
Tonsina from Richardson to Copper - Embick reported as III+, I observed II at put in and confluence with Copper, I think at moderate water levels this will be my next run when in area. Hazards include quick current and observed sweepers. Looked like would combine wilderness with not an impossible bushwhack out if necessary. I think with the reported and observed sweepers, I would probably leave the bike behind for easy exit and carry.
Copper from Klutina to Chitina - Jettmar reported as II, I concur. Looks like a good float, either with or without including the Klutina or Tonsina. Hazards would include channel picking (not sure if that’s an actual hazard in a 5 lb raft) and gauntlet of salmon wheels, dipnets, and a very large percentage of “sportsmen” who are seemingly unable to move 10 feet without an ATV at the confluence with Chitina.
OK if anybody has anything to add feel free, I’ll edit if I remember anything more. FYI Neal at the Chitina WSE NP ranger station, although not a rafter, has a wealth of knowledge and had a compilation of Embick’s original notes on the area (oh for a handheld copier). I did not get further in to add any thoughts on the popular Kennicott, Nizina, etc. runs.