Maxperson
Morkus from Orkus
In combat, while enemies are moving, and they are constantly in motion, even if they stay in the same 5 foot square, you can't get that rope around the enemy foot without it being a hostile act. I.e. an attack. Even if it doesn't require an attack roll, it's still an attack that would break invisibility. Attack for invisibility doesn't mean only the attack action. Any hostile action is an attack that will break it.It is all rules supported.
Tying a rope around someone's foot is not an attack. You can argue it is improvise an action, but there are no rules for making an attack to tie off a rope and would not logically be an attack. There are also manacles which are an object and would clearly be "use an object" action to apply, it would seem to me tying a rope is similar.
But not one that is hostile. It can't attack, so it can't pour that vial on an enemy and cause it harm. The spell text prevents that.The mage hand spell says in it explicitly that it can "pour out the contents of a vial"
No. In addition to an investigation, the text of minor illusion also says, "Physical interaction with the image reveals it to be an illusion, because things can pass through it."Minor Illusion is a spell with specific rules around it and requiring an action to investigate.
That means if I interact with it physically in any way, I know it's an illusion without using an action to investigate.