When the account is deleted I assume that deletes all premium points associated with that account?
Yes, whether there are premium points on the account or not doesn't matter.
I change my ingame account name several times a year. I currently cant change my current account back to Mintyfresh because of the 6 month time out. I dont want my forum account changed so what are my options?
Also additionally what was the rationale behind this decision?
1) Send in a ticket.
2) The new GDPR/DSGVO regulations.
If an account is deleted I take it all of his threads go with him?
No, they only get unassigned and will be displayed as being made by "Guest", I believe.
I have just restarted playing after a three year leave. Will my account be deleted?
No. Any account that is active now won't be affected. It's accounts that haven't been logged into for a year at the given date that will be deleted.
I have another question, when it comes to deleted forum accounts, do the posts get deleted too? Also, lets say if my username on the forums The Nemesis123 gets deleted, does someone else get to create my account and impersonate me?
If your username is deleted, it's possible, though I don't currently know the functioning of the deletion and can't say if there's any blocks on that. As for the posts, see my reply to darkx.
"This means that having different names on the forums and in the game will only be possible by having multiple game accounts, that need to be actively used (at least log in once every 12 months to avoid the automatic deletion)."
Does this mean a player can have more than 1 account? (player has more than one account on same world) This confused me as I thought we could only have 1 account.
No. You cannot multi-account on a world. But you can have game accounts playing different worlds or just being logged into once a year to keep them active.
This update will likely reduce returning players. I would not have returned if my account had been deleted.
We're aware of this. Unfortunately, there is nothing to do about it. However, players will receive a warning before their account is deleted, so if they are using an active email they should have every possibility of preventing that deletion.