Conversation like these makes me wish there was a university that taught "Competitive Gaming Theory & Shenanigans" but one day.
I can probably answer some of these if you want my prospective on it. When I look at a new fighter, I try to see what character fits my play style rather than what character looks top tier or broke, but keep in mind characters who look dumb and what can I do about them in terms of matchup. Usually watching Japanese vids help me determine how the game is going to be in America (like how everyone is going to play Chie & Mitsuru in America when P4U comes out). In terms of what you need to improve in fighting games can consist of spacing, pressure, mixups, execution, optimal combos, blocking, matchup/player experience, and punishing. Rather than looking up matchups all the time, try them out in training and see what moves you can punish on block, how to get out of their pressure and what to do at neutral. When you play someone, usually by the first round it should be a warmup to how their playing and if you can adjust in the next round. You should always think about the character first, then the player next (I often forget that myself).
And every player should learn about frame data and theory fighting.
Josh, I am a button masher and I admit it (especially online). Just know what buttons you need to mash correctly.