Alright, I will give you guys a little tutorial on what I've got pinned down so far. I probably phrased my last post poorly, as there is no 'default free slot' on the Gladiator, however with only 6 hull pieces you can make enough space for a cannon and a small ammoloader. This is not true for every ship - most are awkward to modify. Let me show you.
The default Gepard. Quite powerful despite carrying the smallest caliber gun in the game. The A-9 Sprint missiles are useless considering you can use your cannons to shoot down any missile, so those will have to go. I also haven't really seen the palash anti-artillery system be effective, but I also don't know how to activate it lol. This simple additional engine took a single 4x4 hull piece and the engine itself. So cheap as hell, with a significant increase in speed. This is an example of how your playstyle should define your ship construction. I never really use the AMMs for aformentioned reasons, so we simply remove those and add two additional ASMs. These are also more protected, whereas before if you wanted to avoid wasting missiles on weaker enemies, you would need to be careful they weren't destroyed by incoming fire. Now they are super safe.
The widening process. Do note I have not actually tested removing one of the chassis elements from the leg structures, but I don't think it prevents landing. The game is really quite intelligent about understanding how to interpret your constructions, and the landing legs appear to self-direct in the most useful way. I later confirmed this design was fragile, but you could land without damage. This final step is the addition of a 130mm medium caliber cannon and the requisite power and ammo components. The Gepard is an extremely fast and tough to detect craft, and by adding this extra cannon it becomes a go-to infiltration craft.
Some minor things of note that I have found effective:
-Rooks are awesome, the default bomber craft. Very nimble and the bombs are highly effective against larger targets. When I make the decision to attack a strike group head on (usually just for fun..) I send in two rooks first. With enough speed the bombs will carry your momentum and so you can torpedo bomb from below. BRILLIANT
-Special ammunition is broken, all types. I one-shot a freaking armored frigate with a plain old 130mm armor piercing round! Incendiary is a must buy for the smaller calibers and I just buy out the stores of their stock, since it's quite cheap. Prox fuse rounds are also ridiculous against unarmored ships, or if you can get the undershot on a larger vehicle. Essentially shotgun rounds. However, each type has different flight characteristics and so you have to know what you're up against to pick the proper round. I have found that the larger the caliber, the more effective the special ammunition, So 130mm armor piercing rounds are disgusting, but the smaller calibers don't seem to benefit as much.
-Study the enemy and make note of the armor locations for each ship. Don't even bother shooting those places with default HE rounds - they do so little damage you are wasting your time. Armor will block like.. 10 volleys of even the larger calibers. Buy the special ammunition and use it sparingly.
-You NEED to think in terms of having a main assault force, and a smaller, faster strike group... Gepard is good, Lightning is FAST AF but needs modification to be a good fighter, rooks are fast and CHEAP. Skylark or martingale is necessary, but only one -
you can support at least two other craft to the max strike group range pretty easily. there is apparently no max range, not sure why I thought this. I currently have two roaming lightning + skylark groups, pretty effective!
-For the strike group, equip at least one ship with infrared detection and one with ELINT. You can use radar too, but it will get you found and killed far to easily on hard difficulty. Infrared can be used to hunt down traders if you park your ships on supply chokepoints and lie in wait.
This game is so fucking cool.-the game is easy peasy until you need to engage frigates. Then, you need to think about what each craft might accomplish as it's deployed, and how long you plan to fight with said craft, until you retreat. Rooks are great because you can cause massive damage and escape unscathed, weakening the frigates for your Novgorod or whatever it's called to clean up with the 6 gun 180mm batteries.
-Long range missiles are really cool but expensive, rare, and moderately effective. I found out that if your missiles fly PAST an enemy squadron they are subject to screening AA fire.
-Nukes are fun, but you just get screwed since the first strike group that sees you will reply with multiple. And you NEED AMM for nukes since their splash is RIDICULOUS.
I modified a lightning to carry an extra two cannons, and DAMN that thing is a great fighter. I think it still had 500+ speed too (from default 700+). I too used to think Gladiator was the best, but armor does not work against frigate level weapons. The Lightning, however, is so fast that you are pretty much hitting blackout G forces on every turn, and so you can dodge those prox fuse battery shots that are small ship insta killers.
Oh, and aircraft carriers are expensive and I haven't figured out if you can launch your own aircraft strike groups. You SHOULD be able to, since as a fighting craft the carrier makes little sense. Holy shit though, the little fighter jets give a great sense of scale for your craft. Literal flying cities!
edit: how not to land