Well from what I know of lore in game & Tinkerers words I can answer some of these.
Bat Creatyres are genetically incompatible with humans. MC can trigger the egg production, but like non-alpha members of the species, this will NEVER fertilise. She exists soley as a resource farm.
Same with Spidergirl. She exists as a resource farm. Only Queens can be Were-spiders (have Lucille's genes) the rest are normal & the only way a queen will hatch is if the current one dies (like ants & bees).
Vamps are a mabey depending on if their is a story/mechanic reason but do not hold you're breath.
Goblins have a 1 in 100 chance of birthing a girl. Tinkerer needed more wives & decided a daughter would be acceptable. The rest of the wives we will get through quests (we still have those Cave Goblins to beat) so that one is a big no as M3ntir has already said. Also Goblins dont have much in the way of familial bonds, the children are born to be warriors so their Cheif/dad is seen as their Boss. In the same way they dont refer to each other as brothers or call Shakala Queen when she is their mother or step-mother. Even Shakala barley has a familial relationship with her dad, he intended to turn her into a sex slave.
The familiar is one of a kind bound to MC, her children are not. In game this is because once they are warned off her milk she cant keep them with her "loss of magical tie" the Orb let's them remain until they are fully mature, then they leave. Mechanics wise this is so the engine dosent over heat & blow out the game...
I agree the kids could probably have their money/resource making uses like Rosy's... would have to think about that tho so it feels authentic to the kids in question. (Ex: Mia's could get Firewood, Flowers & Honey. Frida's could mabey help in the garden(?). Julia's could also work the farm for resources perhaps.)
I also agree with more submissive girls. I feel like perhaps the more dommie girls are thing Tinkerer likes (wonder if he is basing them on someone
lol). I mean the most submissive girl (not-BB) is probably Mia & even she can be a bit stern with MC at times...
Pet wise wouldnt say no to a Gater Girl or a Kroggoth.
Wouldnt have a problem with a Werewolf. I know Werewolves in this setting behave more like Werewolf: The Apocalypse, as in its genetically passed down not coursed by a bite. Sometimes it skips generations. Perhaps MC can capture a She-Wolf & keep her in the Vamp Castle. Then her kids would be added to the current army of Gargoyles (& when needed Zombies). I think there could be some fun defence quests for the Castle.
