Can I misty step and place bag of holding inside another bag of holding in the same round (i.e. same time)?

The question is if placing bag of holding inside another bag of holding opens the gate to the Astral Plane (which was discussed here: Is it possible to stuff a Bag of Holding inside another Bag of Holding?), then – can I make misty step before the gate has opened? For example a character runs toward the monster, puts bag of holding inside bag of holding and makes misty step before being sucked through this gate?

Can the Fey Wanderer Ranger be targetted by a creature affected by its Misty Presence?

Wizards of the Coast recently released a new set of subclasses via Unearthed Arcana.

Described in this document is the 15th level Fey Wanderer Ranger feature, Misty Presence, which states the following (abridged for brevity):

You can magically remove yourself from one creature’s perception: you gain a bonus action that you can use to force [a creature] to make a Wisdom saving throw […]. On a failed save, the target can’t see or hear you for 24 hours.

If the creature cannot see or hear the Fey Wanderer Ranger (and, indeed, if they are completely “removed from the target’s senses”), then can they target or attack the Ranger at all? This, of course, is assuming that the target has the standard set of senses.

The document omits any mention the Invisible, Blinded, Deafened, and Hidden conditions, so it appears that the target of Misty Presence is afflicted by an entirely separate condition that isn’t covered by their respective rules.

Why does the Fey Teleportation feat name a spellcasting ability for the Misty Step spell?

From the feat description:

You learn the misty step spell and can cast it once without expending a spell slot. […] Intelligence is your spellcasting ability for this spell.

As far as I’ve been able to determine, spellcasting ability is only relevant when there’s an attack roll involved, there’s a saving throw, or the ability modifier augments damage. In the case of Misty Step, none of the three apply. There are similar cases with other magic racial feats (“Charisma is your spellcasting ability for all three spells,” where one of the spells is Detect Magic).

So what’s the significance of naming a spellcasting ability?

Can a player use misty step to stab someone without attacking?

One time, my sorcerer and my warlock were fighting. The warlock that uses its pact of the blade and hexblade ability to summon a rapier as an action, then as a bonus action uses misty step to teleport right in front of the sorcerer with his arm sticking out. At the time, I didn’t make him roll to attack and let him roll for damage, now I’m questioning it.

P.S. If this is already answered my bad, I’m too lazy to go through all of the actual questions that are similar to the one I am asking now.

Is this part of the description of the Archfey warlock’s Misty Escape feature redundant?

From the Archfey warlock patron feature Misty Escape (PHB, p. 109).

When you take damage, you can use your reaction to turn invisible and teleport up to 60 feet to an unoccupied space you can see. You remain invisible until the start of your next turn or until you attack or cast a spell.

The part I think is redundant is the last part where it says “or until you attack or cast a spell”. If I’ve used my reaction, I can’t make an opportunity attack or cast hellish rebuke or a similar reaction spell, and by the time I can attack or cast a spell again, it’s my turn again, so surely that’s covered by the “until the start of your next turn” part?

Or am I overlooking something?