I see some posts go to bottom and some posts at top of 'thread'...that would be good to know, as to why?

@Dick_Martin Level 5?? anyway -

1. The time is not displayed for replies, but the date is at the bottom of every post.
2. The newest post is at the top of the page, so the first post is always the 'last' post.
3. Most use the @ symbol to direct their replies, see the posts and I'm sure you'll figure it out in short order.

You should be able to choose between a few organization options. I'd switch to the "newest" option at the top of the responses.