Combat and Stealth mechanics related

First of all hello, since this is my first post in these forums. I hope that more maturiry exists here than what I have seen in other forums including Blizzard's own forums...

Anyways... I havent played wow for like a year and a half (maybe longer) and started playing like a month ago trying to understand aaaaaaaall the big changes that took place during that time. I must say I have understood most of whats going on and I am pretty active at the moment. However, the patch applied this Wednesday confused me in a great extend since... blizzard as always, has made changes that they have not explained in any patch notes...

First off, why on earth am I in combat when I am just walking by people who fight with mobs? I am getting locked up in combat MUCH easier than before. I know that this can be solved by me being more cautious, however, I need to know if thats a bug or a general rule from now on...

Apart from that I would also like to ask you if anyone of you also though that Vanish is now by far less responsive than it used to be... I am being attacked by a mob... it casts a spell on me, CoS to take the darn overtimes of me, vanish, and then <Stealth> Fades... thanks a bunch...

Apart from that I was stealthed and tried to crawl behind a darn Siren in Greengill Coast that was fighting with murlocs, she casted that screech (or however it is called) and it took me off stealth... never before... I swear it never happened before :/

Finally and thats a question that I want to ask cause I have no clue of what new abilities (not talents) other classes got... I know "Know thy enemy," I will, gimme time... I was walking around a skirmish in WSG trying to pick my target when suddently (and this happened many times) I just got a golden-like smack graphic on my char (with probably no damage) that took me off stealth... any ideas?

I know its a long post, but I beg for your understanding.

Thanks again

EDIT: blame my vocabulary|||"I was walking around a skirmish in WSG trying to pick my target when suddently (and this happened many times) I just got a golden-like smack graphic on my char (with probably no damage) that took me off stealth... any ideas?"

that might've been the new paladin 51 point talent it looks like blessed hammer. I forget what it's called already. but if that was it you should have seen some damage...|||Friendly Paladins using that skill will also unstealth you, so no damage means that's what happens. Also, elusiveness no longer gives you higher esistance to aoe pells, just reduced damage, so the siren spells which you most likely would resist are now unstealthing you.

Overall, it's become much harder to stealth around undetected. This is almost certainly intentional, as the majority of people play toons with no stealth abilities and so moan about it a lot.|||someone in the Blizzard forums (of the States I think...) said that stealth and vanish are broken and will most prolly be fixed. I dont see why stealth should be nerfed... ok if they know I am around they can aoe and get me off stealth of course. if they aoe and I am asking for it, again, I should unstealth, but walking around with friendly paladins unstealthing me due to one of their effects that just shows something is wrong.