Brush before and after wear. Wipe with damp cloth if too dirty for just brushing. Cream every month or so to maintain the colour and slightly condition it(like the link you posted). Conditioner(mink oil, Saphir Renovateur, Bick4 etc) 1-2 times a year if you want, very very lightly.

Wax polish if you want your shoes to shine(like the one you get in Bata).

I use Saphir for almost everything but no problem to mix brands (cream, polish, conditioner).

Yes. I keep a brush specifically for this near where I put on my shoes. I do it while my shoes are on my feet.