Since we are talking about dreams, I will post what I would like my hardcore mode fro Black Mesa:
-Weapons do more damage (example, 9 mm should be able to kill in 2 shots to the head, 1 to the face, 5 or 6 to the dorso and criple NPC when shooting at limbs)
-Vorts should deal more damage, 23 at least .
-HEV suit should absorb damage progresibly ( 10 % damage absortion at 20 charge, up to 50% damage absortion when fully charged)
-less ammo laying around, dead guards should give a random number (between 0 to 3 ) of magazines, soldiers a bit more.
-HECU should use granades more often, and also the granade launcher.
-Agrunts shold fire on the move, charge at you and trow stuff at you at high speeds, their health should also be boosted and would require at least 20 bullets to kill, and also make them inmune in the chest area (the one protected by the armor plates) to conventional weapons.
-M16’s should be used by the HECU on the surfice, with the benefit of having longer range, more damage (at least 15 to the player at point blank) and less fall damage over distance.
-Ladder climbing guards! I want my little army to follow me to the dead 
-special weapons such as the gluon and gauss gun should “gib without killing”, example, firing a bolt of the gauss to the leg of a hecu would rip it off and leave the guy screaming on the floor.
-rocked launcher soldiers 
-crowbar with an special attack, that is slow, but deals more damage, used to smash heads to unaware enemys
-machineguns! SAWs, M60s, etc. all used by the HECU and able to be used by the player, trading off some of your other weapons.
-more variety to the Alien army. Hecu has soldiers with smgs, shotguns, sniper rifles, basookas, et,cetc. Agrunts should come with a melee variant, equiped with a shield and a huge saw on the arm
-mounted Alien weponary!
-dont know what else xD