I did a bit of online research by watching combat footage of huge explosions and based my own explosions off of them. I'd say it turned out okay, but it's certainly a far cry from realistic. Good enough!
I have been procrastinating on writing the RTS AI because it's super complicated and I barely know where to begin. I've been considering using a genetic program to do it, but that seems really complicated and hard to approach for a beginner at AI.