I haven't lost a country yet (Normal), but 5 are on the cusp.
My reading comprehension is the biggest obstacle really. I built a normal power plant on top of a steam duct (though I would not have been able to afford the thermal one anyway), and I totally missed that you can build satellites concurrently rather than consecutively (ie I thought 2 satellites took 40 days rather than 20). I should really start again - the game is really designed for multiple playthroughs on different difficulties, I think, but I probably don't have time.
The 6 squadmates is a big improvement, though it is a pain to move all that many and put them on overwatch etc
I got another heavy as a mission reward so life is good. True about snipers though, I think the issue is that the RNG can give them a great spell, and then they hit nothing for 4 missions after that.
My biggest complaints are around being able to shoot through walls, aliens spawning out of nowhere on top of my squad, and various bits and bobs with the maps - mysterious gunfire coming from off-map, getting stuck in the void etc.