I am looking to paint my bathroom. I am thinking of going red, but was wondering how well it would hide imperfections in the drywall, or would it show every little thing? Not sure exactly with shade of red I am going to go with or which finish. Thank you.

My house has softwood (SPF) stairs going from the main to second floor. These are the original stairs that used to be covered by carpet. One of the previous owners had removed the carpet and just painted the treads (I believe it's a latex paint, but haven't tested it yet). There are many chipped edges on the treads, the paint is peeling in some areas, I've dripped paint on them during my renos and there is a large gap on a triangular tread that is made of two boards side by side... Eventually I will be hopefully replacing these with either hardwood or putting veneers on top, but for now, I just want to fix up the chips/dents/gaps and paint them again to make them look half decent. So I have a few questions: 1 - What should I use to repair the chips and fill the gap and dents? I was originally thinking of wood filler, but I don't think it would hold up to foot traffic. Essentially whatever I use must be as hard as (or harder than) the wood itself and I need to be able to sculpt and sand it to form new edges. 2 - What kind of paint should I use? I don't think regular latex paint would hold up to foot traffic too well. I was thinking of putting a coat of polyurethane on top of the paint, but I'm afraid it will make the stairs too slippery. 3 - What kind of prep work do I need to do? I was just going to give it a light sanding to make it smooth and and get rid of the paint drops... should I prime it after? Some pics below... Chipped edge [ATTACH]80095[/ATTACH] Chipped edge [ATTACH]80096[/ATTACH] Peeling paint [ATTACH]80097[/ATTACH] Gap between boards [ATTACH]80098[/ATTACH]