Level shelves

[baxters]

I had one pot in the center as well as two on either side- I center pot was large enough to hold the amount of glass I needed. Before I fired I was concerned about that.
I now understand the need for a slow advance and how you came up with that.
3 more questions:

Can I do this on thin fire paper since I am firing to 1500 or do I need to prepare the shelf as I did for the pot melt?

Do I need to go on and remove the kiln wash that is on the underside on the piece?

Do I need to dam it again? ( I think yes). I am so afraid to fire that thick a piece w/o one and I have never done a pot melt w/o one.

My firing schedule for this piece was
600/1000/20
250/1100/20
450/1700/90
9999/1540/45 then to 900/120 and a conservative cool down

The first two this week have alot of popped bubbles on surface, not over an 1/8 diameter. Do I refire with top side up to a full fuse1500 with a dam? Using thin fire or heavy kiln wash? Thickness 1/2 inch.
Or do I flip it over and fire to 1500. I would guess at a soak of 30 min
The need to redM is always confusing to me. Thickness again is 3/8 on one and 1/2 on the other

The firing schedule on the ” bubbled” pieces were pretty much the same except 700/1700/90 & soaking at 1500/60

I really appreciate your good explanations and advice. It is nice to know these forums are here and people are so willing to take the time to answer these questions.
Thanks
Susanne