I've been trying to get past the mission for escorting the Relari. Trying to get through it properly, I've had some issues with DOS Box where my guns won't fire correctly even with sufficient charge.

I've tried using cheats to get past it. I have it loading fine, and when I got there, I used alt+del to destroy the attackers. I activate the auto-pilot to return to the Tiger's Claw and in the cinematic I can see the Relari following. When I land, the debriefing message says the Relari was lost. Am I missing something?

It took a few more tries before I managed to get it. I think I was getting to the Tiger's Claw too fast, before the Relari had come in close enough to be detected.

How do cheats work on this new version?
I remember some of them from the old 386 days, but how do I make it work here?
There are some frustrating missions and slowly my patience is draining after running the same mission over and over again.

It's not a new version, it's the original DOS version and the cheats work exactly the same way. Of course the place where you have to apply command line parameters is different since the shortcuts and DOSBox configuration files created by GOG automatically launch the game. This post explains quite well what to do.

Edit: Sorry, actually it doesn't. The post is from before GOG added the expansion packs. The file you want to alter is "dosboxWC_single.conf" located in the game directory (instead of just "dosboxWC"). But the other stuff hasn't changed. Look for the line "loadfix -1 wc" and alter it to say "loadfix -1 wc origin -k".

Thanks, that did the trick.