Gore is great at this flow; less pushy and not as big as normal flows, more creeky. I prefer it at 1,100 and I think 11 is a great level for a first run, because it's "classic" Gore. But 450 or 550 is a fine flow for a first run.
For a straight class 4 boater, it still would be a step up, I think. You can walk Gore and Tunnel of course. But you need to have some modest creeking skills for sure, even without those 2 rapids. A boof stroke will serve you well in a couple places, and there are some rock-splat-slide-to-drop kind of moves in a couple places, where it helps if you're comfortable USING rocks instead of just avoiding them.
If you've done a lot of class 4 and are very solid in class 4, Gore probably would be good to go for you at this level. You would want a guide, or be prepared to do a LOT of scouting. The drops are kind of steep in places, not very good for read-n-run because you can't really see what's happening until it has happened.