5e? Goblin. Obvious fit for the vibe, and mechanically gies you a bonus action disengage after you booming blade in melee, which covers you for the first 3 adventures. Bonus action Hide will be useful for all 7, especially if you opt for Infiltrator.

Try Villain Actions, a la https://nerdarchy.com/a-mouthful-of-5e-dd-villain-actions-inspired-by-matt-colville/

You’ll notice that the 4s are all hugging the exits – it’s the most lucrative spot. Yes, you have to squeeze in when the doors open to let people in and out, but you also get to gtfo first. You’re not subject to the Showtime kids doing flips, when the Mariachi band walks in you can run out to another car at the next stop, and you aren’t in the urination/defecation areas. Sitting is a trap.