Stealth takes some tactics this time around.. which is awesome I think. Take a shot, move position.. wait patiently.. repeat. Don't just sit there and let yourself be found. Also, mines are your friends. When you see "Caution" that means enemies are searching for you.. they will go to where you last fired. Place mines where you are.. take a shot, move. Perhaps a raider will trip that mine. (they can also spot mines now so you have to hide them a bit carefully.)
I do understand what you are saying about that Forged scene. You are loaded into the middle of a cutscene against very powerful enemies. If you've been playing stealth and not doing anything with Endurance this makes it doubly hard. (Also realize that areas are leveled.. if you can't complete something now, come back and do it later.)
How I did that Forged thingy. Immediately after conversation I jumped over railing to bottom area, crouched and then used a stealth boy, stimpack to heal that initial damage and took some buffjet and buffout. Time is now on my side.. I kept taking buffjet.. got addicted.. didn't care.. Time fly's when you're having fun.
Tip: Remember some drugs stack. You can basically make yourself invincible with drugs to get past any situation.
Also, have no idea what your agility is at but if you plan on being sneaky you need really high agility... the stealth perks alone won't cut it. My sniper currently has 11 Perception, (13 at night.) and 10 Agility. I have a 2 endurance. (at some point I'm going to raise that because I want aquagirl,,, just to swim about in the ocean and see what's there.)