It's possible you will be catheterised during surgery but it will usually be gone by the time you get back to the ward.
Two drains per side seems to be the norm for mastectomy, one high and one low. That does depend on the surgeon.
As for bandages and wraps, I was very surprised to peer down the front of my gown and only see a couple of bits of tape after 2MX (nipple sparing)and expander recons. I gather they are more likely to bandage now than they used to. All this stuff changes, wounds kept dry, wounds kept moist...hard to keep up.
As them, they all do things differently. Marg x