Not really. Earlier sectors often have opposing ships with small crews which helps with training your combat skill.

Yes - and in later sectors the chance for the enemy ships to have clone/med bays increases (on Normal/Hard anyway), which require more coordination/effort to pull off.

Though personally I'd upgrade my teleporter at least one level first, or ensure I at least had a clone bay.

Actually any ship with a clone bay can be a viable boarding ship pretty easily. And at the start crew deaths don't matter as much since they're not skilled anyway (though you'd still want to level them up if you can).

I had no idea there was anything like "clone bays", cool.

They are part of the Advanced Edition content.

Damn straight - I lost count of how many times I played it, or how many goes took to get all the standard ships unlocked.

Be warned (or at least informed) that Advanced Edition compared to standard mode can turn your game on its head - especially as you're learning the AE mechanics. It changes things enough that previous strategies may no longer work, or at least not as well as before - while at the same time, totally new strategies come about.

The Clone Bay is probably the biggest game-changer - I tend to play significantly differently with one than without one. And to think at first I hated the things!

I would say Hacking. So many systems to hack, so few drone parts!