Best practice models, textures for rpg

Hi, I'm a newbie to unity but have alot of experience in programming. I'm also a amature 3d artist. I have a couple of questions regarding the model assets when it comes to a RPG type of game, where Your character updates his armor and weapon alot and even when You start and create ur character at the start of the game (the different models and textures You can select from). In a senario like this, how should one go about making the chars. Exampel below

This is one of my chars, and he's wearing a boot.

Should I make the char and boot as the same mesh/object? And hide the boots texture when he is not wearing it? Or should I create two diffrent objects? Creating a object for each of he's cloth would probably give most fredom in creating cool gear/cloths but what will it do to performance? Or dosn't that give bad performance?

And for textureing, how many uv maps should my model have? atm he has only one, but I think it would be good with atleast two, one for the head and one for the body, so I can quickly swith the head texture when the player creates his char, that way i will like have ten head tectures to chose from and maby jsut 2 diferent bodys?

Tatoes, can I do that in separate layers on the model or dosnt that work or maby draw down performance?

Beard, hair, I gues that would be the same as how one do clothes?

I would really appritiate any help and sugestion.

PS sorry for bad English

Sins

Dyrwoolf