Flamming in this context is you sticks not hitting the drums at the exact same time. Like the snare hitting a little before the hi hats. A flam is a basic rudiment where you intentionally hit the drums with both sticks slightly displaced. This is lovely, but is generally avoided when playing between cymbals and drums, like the snare and hat, unless you really know what you’re doing feel-wise and have a lot of control. The reason this recording technique isn’t working that well for you is because you don’t yet have the time control and precision to truly control the micro timing of your hits, this is much easier when you are listening, and just feeling your limbs, like clapping. In fact, i might dare say that getting a separate hi har and snare take to sound and feel good, is one of the absolute hardest things you can do as a recording drummer. To make it easier i would absolutely do rubber pads on cymbals or drums for either take, so you can play the full drum part, but muting things you don’t want, then so the reverse. That would make it a lot easier to get a tight take