Disabling physics for all props at once and the fire spreading

Hello all! I made a large map for my project, with a lot of different physical objects, and players can move these objects due to the weapons used in the game, which they can’t do. This presents a problem. I can go through each object, and in the collision put Static Mesh (or similar), but there are a lot of such objects, and the map has a lot of buildings and walls with rooms. I would like not to spend a lot of time to disable collision all.

Question 2 “Spreading Fire”
On my map there are some objects that can catch fire when using some weapons(bazooka and so on). Is it possible to globally disable all appearance of fire?