@P810 , thank you so much for your advice. I'm well aware that what I'm heading into is a complete mess
The more I look into it and try to sort it out, the more I'm realizing how difficult and tangled the WP code is to work with. I'm doing it just for fun, but I can't help being completely frustrated with the simplest stuff (such as the BB forums) which keep loading random stuff whenever they feel like. And this is simply due to conflicting slugs, tags, and redirects. I'm doing more troubleshooting than content writing and creation at this point by about 80 or 90 percent and it's driving me quite a bit bonkers.
I'm going to start playing with the adoptables code only once I'm comfortable with the way wordpress runs on its own for now.
I guess I opened this can of worms... and not I gotta lie in it.