Re: lingering questions in my mind
You are, I think, too focused on the facts of what did or did not happen. As others have stated, you know she had a physical affair. You know she lied to you about it. You know the affair lasted for a while and was not some drunken one-night-stand (which wouldn't be good but implies different issues).
She did not participate meaningfully in marriage counseling. She has not owned up to what she did, nor shown true remorse. Her responses to your questions show continued deceptions, minimization of the affair, blame shifting, and rug sweeping.
What you have so far is a totally failed reconciliation. You have not healed from the betrayal. She is not doing any real work to help you heal.
In my opinion, all of those factors are vastly more important than exactly how many times they did whichever sex act, or whether she felt emotionally attached to him. I think your attempts to get better answers to your questions is a misguided effort. You're trying to understand what happened in order to figure out why it happened, and perhaps with that information you think you can save your marriage. The problem is the betrayal itself is not being dealt with.
Your wife is the one who needs to do the hard work in repairing the betrayal. The process requires expert guidance, ideally from a MC who knows what they are doing and will put the pressure on your wife. Your wife will have to feel and express true remorse for harming you. She'll have to see herself as having done something terrible, which is different than feeling bad for getting caught. She should apologize to you, and she should be asking for your forgiveness. She should be examining why she was capable of the betrayal in the first place. After the betrayal is processed, then you start working on rebuilding a new marriage with her, if possible.
Getting honest answers from her about the affair will be necessary, but the content of the answers is actually not a big part of the recovery process. You already know she had sex multiple times with the OM.