1. After a post is moved by a moderator, the OP shouldn't be allowed to move that topic again. He can only ask moderators to move that if there is a legitimate reason.
It's possibly a good idea. Whilst it's rare that it happens, there have been a couple of instances where a user has disagreed with where their thread should go and then kept moving it back every time. Those users just ended up with a ban though. Maybe mods can choose to 'lock' a thread into a particular section if this happens but I'm not sure it happens enough to warrant changes and as I said users would just get a temp ban if they became a nuisance. As for the thread I think you're referencing that's a tricky case. I think due to the wording/promises he made it does look like a scammy HYIP, but I'm not sure it actually is.
2. Meta board can be abused to make a topic more visible. Sometimes it is needed to trash the topic made in Meta or lock it at least.
This would be even less likely I think. Threads can be locked once they're resolved but they shouldn't be trashed. As long as they're not constantly bumped for no good reason they will quickly be forgotten about.
