Merrells should be fine with trouser socks, as long as the fit is good. They are really super comfy and should be great for all day wear. There are also many, many styles from cuter mary-jane like shoes to clogs, so they would work for all kinds of outfits (ok...maybe not skirts).
If you want comfy dressier shoes, I recommend Sofft. I have both heels and flats and love them.

Another brand, albeit way more sporty-looking, are Keens.

If you have a Walking Company store in your area, try there. There's usually a wide range of styles and brands...