With the Noise Marines or DE, I'd pick the Noise Marines. They're part of my Slaaneshi warband, so it'll pretty much be a matter of "Sorry for the misunderstanding" and I can go free.
I'd fire the faulty plasma cannon, it might not blow up in my face.
I'd take the becoming a Space Marine. If I'm a Slaanesh Chaos Lord, I've already gone through the process.
So let's see. I am a Slaanesh worshipping Genestealer with a Daemonette girlfriend who also happens to be a Chaos Space Marine Lord with my own warband. Damn, I'm cool.
This is a warhammer forum. Everything is a military operation.
I have spent the last 25 minutes doing reconnaissance on my kitchen for operation: Cup of tea.