Rarescanner does not only show rares, it shows quest elites that spawn as well. Hardcore addon also does the same, just have to make sure to disable and enable it whenever you need to use AH or mailbox.
Playing HC is essentially accepting deaths over smallest, simplest and dumbest deaths at times, its just the way the game is supposed to be. Whether you died to fall damage that wasn’t really supposed to kill you, or some elite spawning behind you - its a part of the process of leveling in HC.
Impossible to vibe to warrior in vanilla HC? Mate if it was so impossible then HC’s most picked class would not be a warrior. Warrior is meant to be the most difficult to level class in HC but one of the most rewarding as well, buying gear or not is up to you, but taking the risk of leveling a warrior on HC is a well-known fact. You should be packing any class with crafting skills, its a way to survive in tough situations, maybe engineering would have saved your Warlock from the elite, or not idk, but having it would give you an advantage as it should.
Difference in economy? The reason between era servers and HC economy is that era was out for many years and all people do is level and run GDKP’s, so naturally the prices for items sky rocket. If you meant WOTLK, then it is what it is, with each expansion and with the existence of GDKP’s inflation rates rise more and more as there simply are not enough gold sinks in the game to counter-balance it.