addressing 3), every gameworld with catfolk or equivalent will have their own supporting fluff. 5e and PF ARE different. As you are here asking about PF catfolk, use the lore/details in the PF books.
1) This is not defined, if they can even reproduce together.
2) No reason to think so. If Catfolk evolved naturally they are probably no closer related to the Domestic Housecat than a Human is to a lemure. If they were created supernaturally, they may only have a physical resemblance to a feline, but be otherwise more biologically humanlike as far as reproduction etc. In any event, family units are not discussed specifically as far as I know, but it would be unlikely that a mother catfolk who could reproduce with humans would have a different number of children with a human male than they would with a catfolk male.
3) Paizo did change some racial lifespans since publishing the initial races, but I don't know for sure which it was. 5e races of course have nothing necessarily to do with Pathfinder. I would just go with PFSRD unless I knew some reason it was incorrect.
1) If you're asking based on a character concept, that's up to your GM. I'm inclined to say rules wise, you're playing a pure-blood catfolk with some humanish features or vice versa.
2) I agree with Dave, probably same chances of twins/triplets as a human.
3) Rath has it on point.
addressing 3), every gameworld with catfolk or equivalent will have their own supporting fluff. 5e and PF ARE different. As you are here asking about PF catfolk, use the lore/details in the PF books.
That practically covers all three questions-
There are little to no consistant catfolk. This isn't something like kobolds, which are largely born from early role playing games and codified there. It is cat people. People make whatever cat people they want. They make up whatever rules they want.
So if it isn't said in the books- use whatever rules you want in your home game. Make up your own backstory (...god I hope this is backstory. I would not want to be the gm having to deal with cat waifus).
1)
If a human and a Catfolk breed, what sort of children do they have?
Up to the GM, really. And as for Golarion, the only definitely not-allowed half-races are half-dwarves, half-gnomes, and half-halflings. So, half-catfolk is on the table there, if only through the lack of a definite no.
3) Paizo did change some racial lifespans since publishing the initial races, but I don't know for sure which it was. 5e races of course have nothing necessarily to do with Pathfinder. I would just go with PFSRD unless I knew some reason it was incorrect.
They've changed aasimars, tieflings and dhampires as far as I am aware. They all got changed to more human lifespans. Though dhampires were either not supposed to be changed, or only got their age catergories changed and have yet to get the starting ages fixed.
1)
If a human and a Catfolk breed, what sort of children do they have?Up to the GM, really. And as for Golarion, the only definitely not-allowed half-races are half-dwarves, half-gnomes, and half-halflings. So, half-catfolk is on the table there, if only through the lack of a definite no.
They've changed aasimars, tieflings and dhampires as far as I am aware. They all got changed to more human lifespans. Though dhampires were either not supposed to be changed, or only got their age catergories changed and have yet to get the starting ages fixed.
3) Paizo did change some racial lifespans since publishing the initial races, but I don't know for sure which it was. 5e races of course have nothing necessarily to do with Pathfinder. I would just go with PFSRD unless I knew some reason it was incorrect.
A. Three-quartersling.
B. Tieflings have kind of the opposite problem. Oh, sure, starting age and categories got changed, but the random remained the same. That means that the average level 1 tiefling wizard is middle aged.
They are different species. Without magic, or something in the campaign setting that says otherwise, they are incompatible and cannot breed.