I think as long as they are the same on each floor it's doesnt matter which you choose ! IMO arched top is more informal so better iron upper floors - but that's just my opinion !!! :-)

What style of home? That could determine the style inside.

I always like the classic square panel better in cabinets and doors, but that's just a personal preference.

It does depend on the style of the home, but arched paneled doors can easily look dated. Shaker doors with their straight lines are classic.

It is a cape cod style, new construction. Shakes, grays, whites, creams and blues. I do not want it to look outdated that is for sure. I want to keep a classic look through the home for resale too.