Answers

I would still use a vapor barrier. Check your local building codes.

Not sure, but it could be the product. It also could be the surface was not prepared properly first.

Sanding, but if they are deep into the wood fiber you may not get them out completely.

I would wait until they are dry. 15-20%

Borate

no idea. Sorry.

Not much. It is called resin bleed and will go on for years. Might help with a table if you strip it and leave it in the weather for a year before staining again.

Contact your local Sherwin Williams for help.

We use a long nose 1/2” belt sander.

The Rawhide was not manufactured for very long. Any good quality latex stain made for log homes would be a good choice. I recommend Perma Chink Ultra 2 or Ultra 7. Call Dave at 800-564-2987 for help with stains.