An inflatable is a different animal compared to a hardshell kayak. They pretty much sit flat and have limited ability to edge like a hardshell. They also don't track as well as a hard shell since they sit on top of the water more.
I think its actually harder for an experienced kayaker to figure out an inflatable one then a complete novice. For me, the few times I ran an inflatable it felt very alien because of how flat they are.
Bracing will definitely help, but as as you said, its gonna be a low brace. The technical definition of a high brace according the the ACA books is low brace is elbows above the paddle pushing down, and high brace is elbows under the paddle pulling up. Low brace is for stability, and high brace is for more extreme tips and basically is doing a roll without flipping over fully. Generally, if you get an IK that far over its just gonna go all the way and you'll fall out.
Low braces help keep you stable, but I think you are honestly better off just trying to paddle a bit harder and stay straight with the waves. Forward speed is great for stability, and being able to react to the river with some momentum is key.
Keep the thigh braces pretty tight, and then brace against the floor with your ankles. Having a good back rest that you can tighten helps a ton too. You'll never be as secure as a hard shell, but an IK is inherently more stable then a hardshell. You mostly get in trouble with an IK when you hit stuff sideways, so always try to tee up to waves and holes.
Crossing eddy lines in kayaks is a bit counter intuitive. The best way I've been able to explain it, is you want to introduce the bottom of the boat to the current you are paddling into. So, if you are entering an eddy from the main current, you'll actually be trying to lean the boat upstream. You want to actively be paddling into the eddy, since the eddy line is the most unstable portion. The goal is to transfer from one current to the other and not be stuck in the middle. Here is a good video explaining it...
This is with hardshells obviously, but the technique is similar. You won't be able to edge as much, but the weight transfer is still important and will keep you upright. Not leaning and even more important leaning the wrong way, will often dump you out of the boat or flip you.
I'd say try to get out with someone experienced if you can. Nothing like some on the river teaching rather then reading and watching youtube. At least with the IK, if you mess up you just flip it back over and climb on again. Swimming out of a hardshell is definitely more involved.