I don't know everything, but I know a little bit. Here's my take:
One, don't sweat your carbs. If you want to get stronger and perform more, you'll need carbs. Insulin is important, but people tend to skip over the fact that protein causes a decent insulin spike on its own. Coupled with carbohydrate it's a bigger insulin spike. If you are insulin resistant, then reduced carbs make perfect sense. Fat doesn't make you fat, eating too much does. Try keeping carbs targeted around workouts a bit if you have trouble managing hunger and insulin the rest of the day
Like Steven said, is your increased mass in the thighs, midsection and "biscuits" fat, muscle, combination?
And to answer your question a little bit more directly. Yes, you can get stronger while staying lean, but linear gains may or may not happen (it sounds like it wasn't happening if I read your post correctly). You're not going to gain muscle in a deficit, but you can get stronger through other means.
And if you don't think kettleball squat cleans are difficult, I say, step up to the med-ball
- CJ Kim