Why should it?
It has been mire than 10 years now. Utilizing the battlefield was a strength of 4e. With all the upsides and downsides.
I understood the title immediately.
Good analogy. Would you run your car over a cliff or would you know about an invisible something if you were told that?
Also just an interpretation. Wouldn't you open your garage to get the car out?
Oh. I would actually not allow that, as those actions don't help you get away.
Neither would I...
Also: level 5 has revivify. So maybe the assassination should have been successful and on a target when the pary splits. So maybe have them beeing followed for a while. And at some points a perception check or survival check could have given them some clues.
You however want it to divine an invisible wall. Which is not what the spell can do.
See above. You say the magic guides the receipient around an invisible wall. Which is not something an enchantment should do.
Totally ok.
No one died, but it was tense.
Giving enemies species encounters is fair game to me and should have been the advice in the MM or DMG to begin with.
I'd just allow it as a free object interaction.
But that is just a ruling, so no RAW to back it up.
Maybe you could give enemies advantage on attack rolls against the shield wearer instead of -shield bonus, because it still protects but is dangling around annyoingly.
Maybe a cleaner solution...