@Krappers Yah, even before you upgrade your engines, the mercenaries are still a bit redundant in the first exchanges of laser fire, as they are obviously coded to follow you, and the navigational code does the same as the enemy combat AI in trying to hold position - fly towards you, get too close, turn and fly away, so if they catch you up, you can sometimes hear their engines mucking about turning away from you as you speed off into the distance.|
As you get a bit of warning generally for when enemies are inbound on the radar, you can turn away as soon as enemies arrive, and fly the other side of mercenaries so that they definitely get involved, but the whole AI mechanic is a bit basic. Not that it isn't a great idea, of course, and it definitely adds something to the Elite experience.
I've got a Beam Laser now and I've caught sight of Military Lasers at something like 5,000Cr. - madness, but I really really want one. Have upgraded to the IBN shield thingy and the first power whatsit, but it didn't seem to make too much difference to combat performance. Perhaps that's just because I'm in tougher fights, saw my first Thargoid mothership last night, and promptly got murdered to death. As it should be, of course.
Found a nifty computers and robotics 1-jump trade route that is making me bundles of money, but I keep spending it on shinies, and then just drifting from star to star, scooping fuel and getting in fights, even mining the odd asteroid for gold, gemstone and platinum drops which aren't all that rare. Scooping stuff appears to either be broken, or to deliberately allow you to carry more cargo than you have capacity for, I think.