No need to buy kitty wipes, a damp washcloth will do.
Spoiling is really just for the newborn stage. Once they better at seeing and getting around then they'll start craving more independence which can start as early as 4 weeks old. They're going to be wanting to explore, play and practice their skills. Just play it by ear and that part will be fine.
Losing your mom if naturally traumatizing, so their might be a slight delay. But after they regain the sense of safety and security, they'll start catching up.
It's really only the first weeks where they're really needy. One of the cool things about kittens is they're born completely helpless, but hit those developmental milestones very quickly. If you know what to look for, you can very closely guess it's age. The younger it is, the more accurate it is.
I'll see if I can find the site I used for Sasha. Her mom was hit by a car at aprox. 3 1/2 weeks. (yes they can even pinpoint days, they grow up that fast) It was very detailed and informative.