I use Strathmore 500 single ply usually, and I float for albumen and sensitization. I don't recommend brush sensitization for albumen printing, but you might have success with good technique and a glass rod, if you don't want to float it. If you clean the silver nitrate solution with Kaolin, you can reuse it until it's gone or just keep replenishing it and cleaning it with Kaolin as I do.
It is important that the albumen dry quickly to form a skin on the surface of the paper. One way to do this is to shine some spotlights on the paper while the albumen is drying. You can also use a heater in the drying area. Like Blokeman, I make albumenized paper in big batches and it ages for months, but then I steam it before sensitization to be sure it is hardened and to humidify the paper for floating.
I cut the paper to the size of the neg before exposure to avoid gold toning large black borders.