How does invisibility/camouflage work with these instances

passive
W
W
passive
passive
can your opponents see you activate the item or where your ally is located?
asking for a friend.

passive
W
W
passive
passive
can your opponents see you activate the item or where your ally is located?
asking for a friend.
Typically, in my experience, when you activate an item, it kicks you from stealth. There are two exceptions to this - Edge of Night and Youmuu's Ghostblade.
With Taric, people can't see who you W to. This means, yes, you can technically set up a stealth stun, but they will see a prime up of the ability from the stealthed ally's location, without revealing the ally. The ability will look as if it has no source.
Warwick can smell stealthed wounded enemies and follow the blood trail to them.
That's all I know.
I think Thresh express takes you out of stealth.
Zilsta Passive I think pulls out of stealth as well.
I think Kalista line just goes away
Thresh W has to be click activated by the target, thus you'll break stealth/camo with anyone who clicks on it to enter the fray. However, this is rarely an issue, as taking a lantern in or out generally means the fight is on already.
When Zilean activates a level up, the opponents can still see him stop and beam to a spot that moves, but never reveals a champion. Kalista's passive is similar.
All items that have an indicator are not clear enough to make judgements on unless they are really, really close and you can see it moving quickly. If someone has on a Zeke's and they're coming in, you can bet their ally is near.