I like the first choice, the second looks cheap, the third is a bit strange❣️

I like a simple 1x4 or 5" baseboard for a nice clean look so I do not think the 2nd one looks cheap just clean . I don't think the 3rd one makes sense from a cleaning point , We vacuum the top edge of ours every time we vacuum no big deal.

And what do the casings look like, and the window jambs/heads/sills, or are you picking those new too? Door slab styles? Any railings? Townhouse = small = kitchen seen from all over = what style of cabinets and counter details? Basically, you don't pick things independently of each other.

Regrettably, we have a lot of detail on our baseboards and not surprisingly a lot of PITA dusting. I’d choose simplest profile.

@3onthetree kitchen is not hidden but not full open either, but visible enough for style to carry through. Simple galley about 21 ft. long Slab cabinets and white quartz counter with stacked Cloe white 5x5. White oak reclaimed shelving. door casings are simole and squared without much ornamentation. Windows have custom shutters with chunky swuared trim doors are single panel craftsman. black metal railings with rectangular white oak caps.

Please post some pictures so we can see your rooms for baseboard placement.

MDF baseboard is a bad idea for any areas that might get water. I don't think I would risk it.