Ok, yeah after going to the optional area I hadn't been yet (Fallen Angel) and getting the 3rd silenced pistol, killing the guys to get from lvl.9 -> lvl.13, getting Bormin's hog rush, upgraded my 3 silenced weapons to lvl.2, and getting some extra gear for more HP/armor/critical damage...the game is a lot more manageable

Just finished the Sea Titans part and got to the House of Bones. Around lvl.18 now and the girl's AoE skill to stop movement + Hog rush is really helpful. I'd dropped down to normal, but I'm gonna up it back to hard on House of Bones now because Sea Titans was a little too easy with all the stuff I have now.
The only thing I wish the game had was a button to redo your last command if it was a non-shooting command. Sometimes I'll accidently move somewhere I don't want to and then I'm stuck and it messes up the whole fight so I just reload. It's also hard to tell if a nearby enemy is going to be alerted. Like if there's 2 enemies and they're apart enough their circles don't overlap, even if you fully stealth one the noise still somehow alerts the other sometimes? But not other times? The game doesn't quite give you enough information in the UI imo.
Actually I also wish you could run faster when not in combat and just trying to explore and find items. And if there was a better way to find items to make sure you didn't miss anything.
Also I explored in some of the lvl.35/45 areas grabbing stuff without fighting anyone. Got the 4 ammo SMG which I gave to Bormin with the attack twice skill. If he hits both times atl lvl.2 weapon that's 20 damage in one turn without any criticals.... also get enough artifacts to up grenade damage to AoE of 8 damage which I imagine will be helpful.
Game is pretty good now! Definitely worth the $12 for the humble bundle this month.