Alright, after a few more hours of reverse engineering i gave up for now on trying to trigger the traps client side. I tried everything i could think of, like i thought that a player had a hitbox associated in the zoneentry struct - i even found a new value, the players size (strangely, shrink/grow could theoretically persist between zones fine) but it do anything. I also found another strange value, basically it will automatically pan your first person camera up or down very slowly automatically when you login. Depending on the value this can be done faster, but the issue is after a certain degree is reached your mouse will have the left and right side mixed, you are basically staring at the roof and in first person it looks like you are walking on the roof.
I also found that the client had a check when you got near a trap, it removes any invisibility spell - the funny thing is, this only triggers when im standing at very specific locations at a trap. This initially let me believe that there must be some kind of radius i need to set how big the area should be the trap effects, but it was still hopeless =/.
Anyway, i finished the sense trap skill and the disarm trap skill. There are two possibilities to use the disarm trap skill - either click like mad on the trap itself, or use the disarm trap skill button, on the server the nearest trap will be located and then it will be tried to be disarmed. Once a trap is disarmed, it will stop for about a minute and you will not "sense" it anymore since it is disarmed, you will sense another trap if any is nearby, same applies for disarm.
Currently whats missing is obviously that no damage is generated from traps, i had to do that server side anyway for the kunark/velious traps which were just invisible mobs which triggered on proximity instead of "on hit" like the few dozens classic traps in SolA+B and paw.
Instead of 99%, i am now 99.99% certain that there is no damage trigger client side and it was all generated server side back in the days.
= 4380min (73h)