oooh can I ask a bunch of fairly open-ended questions??
question 1 is about the viability of lighter and/or darker patches of fur that (afaik) don't fit into standard coat patterns... so like, squirrelflight's one white paw - is that normal white spotting, or is that weird? or graystripe supposedly having a darker stripe down his spine - does that actually happen?
I had some old ocs with markings like that (odd paws/ears out, or stripes down the back), but in hindsight I'm not sure if those are really possible or if I might want to change them to set patterns/all extremities being shaded the same color... //thinking out loud
question 2: what kind of kits would you expect to see from a black-and-white and ginger-and-white couple? I figure both of them are probably solid(ish) but with a lot of white spotting, and the ginger one's father is supposed to be reddish-brown... if that's not enough to really narrow it down I can make some more grandparents up, but I don't need anything super specific, just an idea of where to start with the sons
question 3 may be kind of dumb but is a tabby/tortie pair at all likely to result in a torbie?? it seems logical but it feels too easy... I know tabby is apparently dominant but idk how it interacts with anything else. (my real concern is that I have tabby+torbie and tabby+caliby sibling ocs, and I'm trying to decide if that makes sense or if they should stop being littermates and just be friends)
Happy to answer em!
Squirrelflight's white paw is white spotting and is genetically viable! Though neither of her parents have any to speak of... (coughs.) Graystripe's dorsal marking is not, though - stripes are never selective like that! If anything, he'd be a tabby of some sort if he has a stripe like that, but since he isn't, it's not realistic at all.
Having 'darker' or 'lighter' fur patches also isn't quite realistic unless they're explicitly something like tabby striping (spotted mackerel or spotted classic, for example) or tabby with silver tipping (pale undercoat, darker top part). White patches are kind of case by case - white starts at the extremities (paws and muzzle and belly, rarely tail-tip) and extend upward and inward, rather than starting on, say, the ears or the back and growing outward. Imagine it like cats have invisible 'seams' at the places the white starts!
Question two: It's very much dependent on their hidden genetics as well as visible. If I were to assume that both of them weren't carrying anything, then their kittens could likely be black, tortie, or ginger with white that depends on whether they're high white (SS) or low/mid white (Ss). If both are Ss, then there's a chance that none of them will have white (but Ss and SS would still occur). If one of them is SS but the other is Ss, then you'd have 3/4ths high white and 1/4ths low white. If both are SS, then all of them will have high white. Depending on the ginger cat's agouti (tabby) gene, then you may or may not have tabbies in the litter.
That said, 'ginger brown' could probably apply to a cat that displays cinnamon, but it wouldn't show up in the kittens unless both parents had/carried it (and the same goes for the ginger tom's kittens, too).
Question 3: Yes! Absolutely! Oh my goodness. Tabby is dominant so torbies are very easily dominant over torties, considering. The tabby gene is formally called Agouti, and dominant (thus, AA/Aa cats will have tabby, but aa will be solid). To give you a better explanation of specifics:
AA x AA = All tabby kittens (or torbie, if it applies)
AA x Aa / inverse = All tabby kittens (or torbie), 1/4 chance of kitten carrying solid
Aa x Aa = 3/4ths tabby/torbie, 1/4ths solid. Pretty good chance that tabbies from this batch will carry solid.
Aa x aa = 3/4ths solid, 1/4ths tabby/torbie. All tabbies will carry solid.
aa x aa = All solid/tortie.
For the record, all ginger cats are tabby, despite whatever their agouti set is - it is just much fainter if they're genetically solid.
Thanks for asking!