Best of Luck in the Course. Good job! Homework #1 Done!
Most of the weakness you wrote can easily be fixed by posting hands (analyzing your session). We will start writing feedback to your play. Usually negative feedback will put you into thinking phase and trying to fix all those leaks. It's almost the same as you lose money, you will remember it more than winning part. By this situation it's gonna be that negative feedback you gonna remember and try to avoid them next time.
Also why should you defend the blinds very loosely on smaller stakes? Even if you don't then it's totally fine which would even be fine. The more confident and the better your skill becomes the more you can adjust your game-play to it.
Overestimating the skills of the opponents is somewhat a leak I'd say. Usually you will either Call him down too loose or either try to just bluff a wrong opponents. Try to find out the opponent, for example don't bluff loose opponents, don't try to play aggressive opponents and just wait for a hand.
Other part of the game like adjusting to the opponents, mental math and stuff will be teach to you with time and experience and of course into that you also have to spend your time for example reading articles, watching videos, attending on coachings, posting hands, overviewing your sessions.
Tight style is usually called playing selected hands. Like following the Starting Hand Chart. Aggressive should be also pretty clear that already the word says how you should be playing. But the problem playing aggressively is that you have to watch that you don't play too aggressive. Find good spots, find good targets. About The tight-aggressive strategy you can read in this article: "What is the Big Stack Strategy?"
Hopefully you will enjoy the Course. Some points earned.