1. Dungeonguru kinda covered this.
2. So here's where it's complicated. As you noted, a lot of abilities are set up for use by multiple monsters. I went through earlier this year and tried to identify all duplicate abilities across the then-released content and create modular abilities for each of them.
Here's how they work: you create the ability like any other. Then, you add an eval script to it. Take a look at Air Form starting on line 205 of
the PotA monster file. It uses tags called "abText" and "abText2" to define variables that will be specific to your monster. See the eval script for how to include them.
Then you make your monster. From the monster screen, you bootstrap the ability to the monster. Let's call our new monster John Airguy, and let's say he has Air Form. I'd bootstrap that version of Air Form. Then, still on the bootstrap window, I'd set new tags. I'd set abText to be "John Airguy" and abText2 to be "He".
When HeroLab pulls it all together, it's going to run the eval script on the ability. It will see that when bootstrapped to John, abText and abText2 should equal what we set it. It then inserts our John-specific text into the description.
I have very shoddy documentation of all the abilities I made like this, what ones already existed, and what files they're each in. I need to upload that, and I'll let you know when I do.
3.
Upload Instructions