"On the other hand, these cabinets are the "cottage-y character" variety;
you can tell that they have a bunch of coats of paint already"

Is that the kind that the hinges are painted, and there is so much paint on the doors they don't close right? And since it's latex paint, the doors stick closed as well?

At any rate, everything needs cleaned really really well, and a light sanding is not going to hurt you, or the cabinets and will make for a better paint job.

As mentioned, cleaning is most important.

Consider Chalk Paint and apply a few coats of compatible wax.

Step #1 Clean them well. Vinegar and dishwashing soap work a treat

Step #2 FORGET having to sand because

Step #3 You prime them with Zinnser 123 - a primer that sticks to anything including vinyl and polyurethane,

Step #3 Paint

On paints, I think the chalk paints are the latest frou-frou fade. Had an Annie Sloan dealer tell me they DO NOT hold up in kitchens and baths.

IF you want the buttermilk finish, use Old Village Buttermilk paint -- stuff is so tough you can use it outdoors. It is the oldest paint company in the US - been around 198++ years and is still owned by the same family.

In the kitchen give what ever paint you use a nice couple coats of gel varnish -- either Old Village Clear or Bartley Clear. (Bartley is the crème de le crème of find furniture making stains and varnish.) You put gel varnish on with a cloth.

We painters (professional) would still sand (lightly)

If you sand it, you won't need to prime it. So choose your battles

I would not use chalk paint for kitchen cabinets. I don't think it will stand up to the hard use kitchen cabinets get. A good quality cabinet paint is what I would use, sanded and primed first. You might get away with skipping the sanding, but why take the chance that your paint will chip easily? You want that paint to adhere well, and sanding and priming will ensure that it does.

Just because manufacturers now claim you don't need to sand doesn't mean we don't sand. They are trying to sell paint to lazy people don't forget.