First of all, I commend you on recognizing where you need to grow in your game. With that being said, its probably easy if you understand what each of those aspects actually accomplish. For instance, do you know why you want to Kara Grab? Why Focus Attack? One thing I can say is that Kara Grab isn’t necessarily basic to the game, but it certainly is an added move if you can pull it off consistantly.
My advice is to practice in training mode (and even in the trial Barrel Buster Stage) some of these things. For instance, Focus attacks are good because they accomplish a few things:
-They have varying levels of stun (focus crumple), so it makes setting up your most damaging combo a lot easier. Lv3 Focus attacks are unblockable, so charging one makes people afraid to eat it.
-They have Hyper Armor (which means you can absorb 1 non armor-breaking normal/special.)
-They are good for absorbing attacks and setting up counter hit scenarios
-They work well for absorbing projectiles
-They help you dash in and out of cancellable moves (back or forward), which even further sets up your options
You may also want to practice your kara grabs (preferably with ken since its most noticable that you’re doing it) in and after block strings, which will help keep your moveset unpredictable to your opponent.
As for backdashes, its pretty obvious you can you that in many of ways. One might be to make your opponent use a reversal on wakeup, and after backdashing, you punish their recovery. Backdash also works great on your own wakeup, which helps you escape from some jump-in attempts. Backdash is also a great tool (especially if your character has nice footspeed) to control space in your footsies.