Once you are in plex behind the gate in low sec just a bit of caution and experience how to use directional scanner, you are almost invulnerable. Of course, low sec is full of trigger happy guys, and you may be scanned down and ganged. Sometimes it is pathetic. I had few situations when I run 4/10 with Ishtar and 3 minutes since I started battle ship and Falcon/Rapier popped up if front of the plex gate. BS even can't enter the gate tho.
But lets see at the situation when you run plex with Comet as tank and Daredevil as DD (damage dealer). from possible pirates in local. If they experienced enough, they can take chances, but also they understand 2 facts: 2 fast ships very difficult to catch up and both pilots are in NPC corp with just a couple of weeks trainings. They fly expensive ships, and may be (probably) alts of very experienced pvp/caribears running mission/plex. It can be set up and they can be fitted as heavy tacklers, fitted with tracking disruptors/sensor dampeners, who knows.
Obviously, they know what they are doing. It would be waist of time to go after them, probably.
Of course, some people may try, if they are bored of gate camping. But chances are slim.
But just imagine if you run the same plex in drake/caracal or even in Pilgrim?
They will be up to it 100%, to kill this "damn noob.
Been there on both sides, have t-shirt.