I've always felt intimidation was a under utilized skill and that swashbuckler never really felt like it really captures what a pirate should be... too Errol Flynn, not enough Dread Pirate Roberts. So I came up with a dark version of the subclass that I call Marauder.

So the goal was to make a intimidation into a workable mechanic and create a rogue that literally scares victims into giving them a sneak attack. I've tweaked and rework this thing a number of times, starting from incredibly overpowered to I hope a bit more tuned, and am looking for input from a wider range of players.

https://www.dndbeyond.com/subclasses/181459-marauder

Any advise or constructive criticism would be greatly appreciated.

This is pretty well designed good synergy and not too powerful. I do have a few balancing and wording tweaks to suggest:

1. For murderous intent, instead of "blinded with terror" how about "intimidated and flinches"
2. Also for murderous intent, maybe creature with advantage or immunity against being frightened have advantage on the save.
3. For dreadful provocation, it is probably intended that the target be within 60 feet, but doesn't specify that (and it should).
4. Also, give DMs the option for provoked nonhostile creatures to become hostile by adding "...may become hostile (DM's choice), otherwise..."
5. And the cloak of the dread bonus of menacing assailant needs to be reworded, I'm not actually sure how much of a bonus sneak attack is getting here (1d6 is fine)

Great input. Definitely will tweak my wording a bit.

Menacing Assailant would give an additional 3d6 to 1 sneak attack per round if the PC has 20 CHA.

That might be too much.