Newby Questions

[Venger]

Hello
I've been a long time RW user.
I just purchased the HLC 5eSRD, have the Community content stuff and HLC is magnificent.
Already created some chars and and npcs and integrated them into RW
Neat
But I'm a total noob when it comes to anything deeper
I realize HL is system agnostic, flexible, and there are several things I want to do, which means much learnings for me

1. I want to copy an existing chr/monster and make edits.
I want to create a pirate swarm instead of a dozen individuals to ease combat load.
I want to edit existing data, the Race: Swashbuckler, who has 3 attacks. 1 dagger, and 2 Rapier.
I want to edit so they have 1 Pistol shot then 2 club attacks (with the butt), among other things



2. We are rebooting Spelljammer and I have a suitable conversion system that I would like to start plugging into HLC to learn it so if/when official SJ is released, I have a heads up on it.

The spelljammer Im using is compatible with 5e, but much would need to be altered for a "Ship Character" so, should I work with the HLC 5e game system, or build new?
Where do I start?

Better yet is there homebrew 5e Spelljammer content available?

And finally for now, what is Campaign Theatre and how do I initiate it?