@PinkyCustomWorld Yeah it's kinda weird but all household members, including pets and toddlers, will need a regular bed for counting purposes when trying to add a roommate. Even though a dog will never even use a bed and a cat will sleep wherever the heck it wants anyway! xD As far as I know, it's even worse with a toddler because you'll need a toddler bed plus a regular bed! (Someone might have to double-check me on that one).
That's pretty cool about those mini-kitchens, I've never tried that. I usually just have my Sim cook family-sized meals and let the roommates eat from my regular kitchen. It helps build up my Sims cooking skills faster. If you don't mind, maybe add another post every now & then to let us know how it's all working out with your roommates. I know there are other Simmers in this forum who love reading about stuff like this. This is a General Discussion forum so no one will mind, as long as it's game-related.
I won't add any spoilers here but don't be surprised if you run into some real dud roommates from time to time. If any of them seem like they are giving you too much trouble, just do a search for "Roommates" within this forum and you'll find a few threads with suggestions on what might help.
Good luck and have fun! :D