There is no floor drain in the Xpress. There is a drain slot behind the seat box that drains out into the bilge. You raise the seat box lid, and spray it out. We vacuum or pick up the bigger trash in ours first, then just spray it out and let it dry.
Minnows shouldn't cause you much trouble if you choose carpet, I sling em all over the boat when the fish are aggressive, and I just pick em up and throw em overboard to the birds. LOL