Probably a combination of(a) and (c), but shrinking is a problem with most caulks that are latex based.Dap makes a latex caulk that contains silicone and is paintable. The silicone allows it to stay somewhat flexible for contraction/expansion issues and shrinks less than latex without, but will shrink on larger gaps. Polyseamseal all purpose adhesive caulk is another decent product that remains flexible without silicone, and is paintable.Less shrinkage with polyseamseal as well.Sometimes gaps require more than one application.

Look at some back issue of Fine Homebuilding. Within the past year they have had an article on doing sloped crown. All you need are the correct cutting angles and methods.

Okay. I'll try to take pictures today and upload them. Thanks.

I’ve heard that you could/should cut the trim color by half or 80/20 or something too. Is that a good idea Not a good idea. It's a terrible idea. I don't think the people who suggest this have actually done it. Or else they haven't seen it done with many colors. Alabaster "cut by 50%" is a weird greenish-yellow dead gray white. I don't know how SW "cut" the formula. I didn't look. And who knows how the staff at your SW would decide what "50%" means. Most of the colors we choose for interior use are near neutrals, muted, chromatic grays and whites. The amounts of colorants are small to begin with - there's nothing to "cut". It's not mathematically possible in some cases and in every case it's up to the person mixing the paint to decide how to "cut" the formula. The other completely terrible horrible idea is to get a gallon of white and "add it" to your wall color. That has inconsistent results as well. Most of the time you can't even tell white was added so you end up with 2 gallons of a color that you were trying to change instead of just one. It's a mess. In addition, if you do add white and use it, you HAVE to save a quantity of the mix for touch ups because you'll never mix that color again. Ceiling can be the same color as the walls or a different color of white. I'd suggest a SW match to PPG's Delicate white to go with Alabaster on the crown.