I'm about to add treads and skirtboards to my stairs and new base board above and below stairs. My questions are:

1. What profile is typically used on the inside and outside skitboards for colonial style stairs? In some books I have it appears to be base cap molding but I'm not sure.

2. I'm having real difficulty deciding the base + skirtboard profile. My issues are -

Base board thickness should not be more than 1/2" since my door casings are 1/2" proud of wall.

I don't think I can safely make a housed skirtboard from 1/2" stock, can I?

If I make skirt 3/4" thick, what is the best way to transistion to thinner base?

Thanks