SkechersWomen's Reggae Fest Willows Flat, Black Mesh, 8 M US

Normally 8.5, need a non-existent Narrow, so even though some say order larger, that would be looser, so is 8.5 likely to be too loose in the heel?

Is the toe box roomie enough for wide feet

Que significa B (M) en las tallas?

Normally wear 5.5. Do I need to buy half size bigger or smaller ? I get confused because one reviewer recommended 1/2 size smaller other said bigger.