I do think it's rude to host a *housewarming* party and have it be potluck.
Potlucks, in my opinion, are for situations in which there is an outside framework or structure or organization that means the party is completely for the benefit of the "organization."
Like, a club, or a church, or a family, or a big cohesive group of friends.
But a housewarming is for the benefit of the householder--it "warms" their home, breaks it in, so to speak, so it should be something that the householder hosts. Feel free to take people up on any offers of "can I bring something?" And feel free to call a few select close friends and say, "Could I ask for your help? Would you bring XYZ food?" (Add to it the costom of bringing a housewarming gift, and it's really bad form to announce it as a potluck.)
I don't care about the shoes.