1)Plop it onto the concrete floor. As long as it is on a stand…no problem.
2)Wood shims between floor and stand is fine. Heat is the concern. NOT between stand and kiln.
3)Assuming you are talking about washing the kiln and not the shelf, any brush is fine. Just slather it on. Haik brush etc are for shelves and molds. Someone else would be better answering that one. i only use thinfire paper.
4)Unless you are going into the kiln for raking, you do not need glasses. Short, incidental viewing of the hot glass (such as a quick view to see where the slump is) is not of great concern. Same is true with gloves. I use welders leather gloves but i do not go into the kiln when it is over 500°F.
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