I don't have an answer for the Q regarding sex. But with the ring- my experience was that H took it off first way before BD and he gave me a believable reason (at the time). And after BD I felt extremely hurt and vengeful so I took mine off after a few days as well. But in the last R talk that I initiated, H actually said he wants to file, and commented that I took the ring off and said the ring was his glimmer of hope in us. Basically blaming me for throwing our hope away. Which totally didn't make sense to me because he's had his ring off this whole time!! Which I just added to the many things on the list of things I cannot reason with him right now. But after the D word I actually chose to put my ring back on, and I told H that I'm still in this, I'm not giving up. I said that I will take it off when our M is truly over.
