Slab and other buiding problems

Anyone else having issues with slabs? I was trying to make a small bridge over a gap that I dug, and the slab tool is acting all weird. If I build a 2nd level of slabs, the tool kinda locks to that second slab level. Also, the template placer is being annoying. I made the bridge template after several irritating trys, and saved it as a template. Then when I tried to place it over the gap I had dug, the game refused to show it as a valid placement despite it fitting perfectly fine if I build it there from the custom menu. Finally, I have a stilt house template I saved from a previous game that is meant to be built in the water. Instead of snapping to the highest available ground under the water, it is snapping to the surface of the water and dropping when you place it, occasionally crashing the game.