I don't see a lot of questions, but I do notice that you phrase a lot of your questions as "what if" questions.
While I shy away from down-voting, the "what if" spin on a question forces it to be less constructive.
For example, your question regarding the result of a group-patronus cast in a sphere around a dementor. Your real question is regarding what happens to a dementor when encountering a patronus. You trivialize what is otherwise a good question by asking for the results of a situation that doesn't even seem remotely likely to happen in canon.
Your question about the veil would have been better if it asked what exactly the veil is doing. It's de-valued by asking "what if Voldemort went through the veil?". Why? Because he never went through and there's no chance for him to in cannon, so it detracts value from the question.