Care to take a shot at explaining why tiles acted how I described solely based on the change of that single server options?

Changed them on the serverside, maybe?

Nope clientside.

I was using a GMAP. And I was unable to even read a tileserverside. So I just did it clientside but that started acting VERY buggy untill I played with savelevels.. then everything just worked. And I was the only one on the server at the time.

If using updateboard within a clientside weapon it will automatically trigger to serverside and affect it for other players.
If you do this within a clientside NPC script however it will only be visible to you. The trouble here is that it's problematic to do dynamically in the same way you would cut a tiled bush, plus you'd then need a timer to restore it to its original tiles. For something like a one off change to a levels tiles within a quest it's quite easy.

Thank you