Looks like you've got a good early aesthetic design going on and the framework for a finished product, and you've divided your power generators into separate rows, which is good. You'll want to make sure your power capacitors are all connected, giving the biggest bonus. That's not all-important though, it would be better to invest in more generators if you're running into power problems.
And yeah, using secondaries on the salvager arrays at this scale isn't getting you any advantage in salvaging power, but its always nice to have that cannon secondary on a small scale so you can keep them running non-stop.
You're going to want to keep up with that design by purchasing both system blocks to fill it out and improve performance and hull blocks to complete the exterior appeal. Remember that thrusters, shield capacitors and rechargers dont get any bonus from being in a group unlike the power and computer-systems blocks, so you can use them as putty to fill in excess space.
I would strongly suggest putting one or two tiny turrets on the exterior, covering it from both sides. Use a cannon/cannon system as small as 1 block each and set them to target missiles. That will give you extra protection against missiles, which are the biggest threat to a small vessel like that. Also, make sure you've got the power generation to run a radar jammer! Cloaking isn't necessary, but radar jamming will prevent pirates from noticing you at range, which is very important when trying to mine in such a vulnerable little craft.
