Somehow I hope that the game is as forgiving as it is brutal.
Oh don't be so shy, you have survived so far, expanded the operation, got some veterans trained, and ended all months with a good score. It's not that you're failing, it's that in Piratez, you have to redefine what you constitute as a success and what is a fail. You don't need "A" grade. You need "Not-Dead" grade. It's still XCom, so it is forgiving (especially since the enemy force escalation is much less pronounced than in vanilla XCom - eg. enemy weapon loadouts stay the same no matter how long you play), forgiving with ocassional bouts of brutal rage, that is
You don't have to worry about killed Swabbies so much (they're cheap), and... In general, you have to let go of unrealistic expectations that the original has taught you (an implacable, if bloody march to victory with millions of $$$ and tech raining from the sky, and 8 bases by May) and cherish your modest successes!
Nobody said it's gonna be fluffy kittens and rainbows, and Piratez WILL deal you painful blows from time to time, just accept it and move on. Especially since your mindset seems to be just perfect - optimistic, cautious, smart. But sometimes you also need to indulge in pure aggression. I'm usually putting a pretty low priority on live capture, I'm getting less money and tech that way, but that allows me to keep more soldiers alive. Live capture is what I am doing in the final stage of the mission, first 2-3 turns is just "kill everything in sight" mode (unless there is a very good opportunity to catch a very juicy target, that is). That way I am able to often break the enemy morale by turn 3 and once that happens, it's just mopping up, with an occassional run-in with a suicide bomber.
As for the tech tree, I'm trying to make every path viable - but once you select a single path, keep on it. Ivan prioritized melee so he's right to go melee, with Metal Armor finally in the fold and the Tech Blade quite possibly coming soon, he'd be able to take on most normal enemies in melee. So it's only natural he tends towards heavy-melee loadouts. Rushing munitions is another path that allows you to be pretty set up for firefights by early March (delays oftentimes due to the lack of proper loot to research). Both approaches need some support too, naturally - explosives and armor. Tac Suit will protect you from small grenades and small firearms, and the Metal Armor will protect you from small lasers. Choose wisely
Sure there will be Stamina cost now (realistically, melee combat SHOULD be tiring just as running is), but you will also get more melee-supporting tech and alternate combat techniques (attacks against enemy Morale, for example - you will still have to make the kill with a blade, but there will be new ways to make that more safely - so the general direction is less wild swinging, more carefully executed plans when a few melee strikes will be enough). Bows will be back with vengeance too (not as OP as they were in the old days, but once again quite powerful on hi-stat soldiers).