2) I'll have to look into these - thanks for telling me!
3) Unfortunately I think playing simple chords in a band, when you and the two other musicians are 17, doesn't really qualify as being quite the musician ahaha thank you still!
The more obvious upgrade would be a new microphone to replace the Kenwood you are currently using. An SM-58 will last you a lifetime or if you have a bit more to spend something like an SM7b will be a great investment particularly recording in untreated spaces.
Also, you could try recording the midi information of your electric drum kit and then loosely quantising/editing the takes to retain the feel. You can map these to Logics in-built drums which are pretty great.
Congrats on finishing a body of work, most don't get that far!
Not always an option depending on where you are, but often you can find an audio-rental company nearby. It's hard to go wrong with the mics I mentioned above though. Keep it up!