According to
this thread, you can run memory viewer in dolphin's debug mode by inputting Dolphin.exe /d in the command prompt (run -> cmd). I just tried it and got it to work.
In all likelihood holding B will not make the cursor any faster (should always move at most once every 2 frames) but it will cause the camera to keep up with the cursor movement, which is generally more pleasing to watch I find. Though, in some cases it's actually faster for the camera to follow the movement as little as possible as to minimize camera transition... Kind of hard to explain, I'd have to show you where it's used in Toothache's FE6 TAS.
By C-stick I assume you meant the analog/control stick since the c-stick only affects camera angles. They will probably come out to the same, but definitely test both because you never know.
Now once you get memory viewer working, it's very important you locate the address for the RNG. Isolating it will be rather tricky because you need to find an action that burns only 1 RN at a time.
First, see if you find an address that changes every time you move the cursor diagonally 1 square. I'd do this in prologue. Select Ike, move the cursor up+right in 1 frame, press b to cancel, check memory viewer, repeat. If path drawing is what affects the RNG like in the GBA games, you should be able to isolate the address(es) fairly quickly.
If that doesn't work for some reason, try landing a low% crit (maybe 3-5%) and search for a value less than the displayed crit rate. I wouldn't bother with hitrates since those use 2 RNs and level-ups will use at least 8. If you're lucky it's possible acquiring desert items only use 1 RN, though they might use a different RNG altogether like in FE6.
