Advanced support is only necessary if there is some technical issue that can't be resolved by normal means. For example if someone is having some type of an issue that they just can't figure out even with standard help via a ticket and forum, and they want me to login to their server and debug it for them, then that would fall into Advanced Support.
Advanced support is pretty rare, out of all of our tickets and help on the forum I maybe have a couple a month.
Yes, the license for the version you currently have installed at any time does not expire, it's good for life. You only need to renew if your access has expired and you want to download a newer version.
