when can I delete a thread?

[Talei]

Simple example and two errors... eh.
I tested this code and It didn't crash application, so I'm a little bit confused about that.
Please correct me, as I'm self taught and can misunderstand some aspect of signal/slot mechanism.
I use disconnect to ensure that object is not connected to anything before delete, and at that point object should have no connection, and then simply delete the object, so the slot is not wired to anything and AFAIK should be treat as function (this is how I understand it from the docs, so probably I understand it wrong).

Also I just look at the qcoreapplication.cpp post event (because logically there must be the difference between delete and deletelater()), that is executed with deletelater() and from what I can understand:
when I use delete object, I delete only the object and event are still in mem.?
when deletelater() is used, I delete not only the object but also all the events associated with this object?
Or I'm completely mistaken with this?