How to play TMGs?

[Altiea]

So, this is gonna sound really silly, but what should I do to effectively play with Twin Machineguns? I love TMGs, and they were my go-to weapon in Nova (Dancing Sweep was the most busted thing), but going back to PSO2 afterwards made TMGs seem really, really slow in comparison. But I want to figure out how to play them, so I'm just wondering what the go-to PAs are, how often I should rely on Chain Trigger, Showtime, S-Roll, etc.

[Xaelouse]

Read:
http://www.pso-world.com/forums/showthread.php?t=200779

http://www.fulldive.nu/category/pso2/gunner-guide/

About relying on those skills you listed:
Chain Trigger can be incredibly powerful and also at times it isn't really worth it. It's good for getting out tons of damage quickly by getting the chain up to 18-32. It will see a lot of use during a big boss EQ like Magatsu, during boss stuntimes or during key moments you'll have to play more to find out.

Showtime should see use way more often, especially with high time and one more time which require not getting hit often. Thing is, the skill also provokes enemies/generate hate every time it activates, which can be dangerous and counterintuitive to the focus of not getting hit to the point where sometimes it's okay to take some damage anyway.