Since most of the buildings are from early 1900s (narrow hallways), and a number of them have steps up into them, many will not be wheelchair accessible, but they have enough going on outside of the buildings where that may not be an issue. The inside portion has elevators and ramps to assist those with wheelchairs. If my memory serves me right, the paths are smooth for wheelchair though they have a couple of "steepish" inclines for you to push the wheelchair up and down since they are trying to show what the mounds used to look like when they were protecting their homes from the sea and some of the parts of the old towns are on those mounds, which can be a little steep.

There are two parts to the museum, outdoors museum and indoors museum.

Outdoors museum: Pathways are smooth. I believe that access to the houses can be an issue. In the outdoor part you will find actual houses from the past that have been moved / rebuilt to this location. Houses from early days were not really built to be accessible for wheelchairs. Some buildings will be wheelchair accessible. There is quite a bit to see. Outdoors museum is not open all year.

Indoors museum should not be an issue at all. There is an elevator and paths inside are wide and accessible.

Both indoor and outdoor museums can be visited on the same ticket, and each can also be visited on its own. Even if you "just" visit the indoor museum, it's worth it.

I'm unsure on the accessibility for wheelchairs however on searching your query it does provide wheelchair access. I would suggest contacting the museum directly on the smoothness of the paths etc. They all speak good English .

Yes

You know it was pretty smooth but then again your experience may be different from mine.

No, I would not recommend that, uneven pathways as well as stairs and cobble stone.