The surface you set the tube on to roll the patch has to be solid, I like vices that are rounded,, and roll it hard, get all the air out from under the patch and mush the patch on.

Yes anything will do but use the correct tool, a roller, it's what makes life fun.

As it's contact cement, the longer it dries before joining, the better the bond

Clean both surfaces with an alchol swipe before applying glue