Health bar:
Health used player' health and max health. i dont think that you need 1000 hp for players, since you have custom armours that you can set options which may provide good defense.

Energy bar:
Used in times when you run(holding SPACE). It was planned to add mass and speed that would have direct relationship, so the "0.00kg" in ur inventory is just a calculation, it doesn't affect your speed.

Armour bar:
Armour provide static defense. But anytime you being hit your armour is slowly destructing. The armour bar would show you how much structure left.

Radiation bar:
In fact radiation is have been not added on maps/locations, but added radiation calculations. So you can set your radiation to see how your health would be reduced with time depending on radiation strength.

Hunger icon:
Appears when your tommy is hungry, in the lua code you can find how does it work. Also sprint affect hunger a bit.

Bleeding icon:
Appears when your bleeding level is enough to damage you. Anytime you being hit there is a chance that it would leave a wound.

Items:
-Consumable items:
bandages, medikits, non-stop, ammo and others is used to keep you alive during or after a battle.
-Custom armours:
armours, that made here is available to wear, they provide some defense and other type of defense, the calculations are working, you can look into Items.lua to learn more. Also you can add you own resist type, but you wont have more space in the inventory for huds, is not planned to provide very much resists.
-Weapons:
weapons are made with custom ammo thingy and using MODS to change skins, so when you turn on your server you have to use "Mods" and set checkbox on the S.T.A.L.K.E.R. - The Lost Land mod to make other players also to see ur changed skins of weapons and other things. Used original weapons to have no problems with bad visibility of "custom" weapons...
Bonus: if your weapon is having at least 1 round, reloading it would cause you additional 1 bonus ammo(:d like in real, huh?)
-Artifacts: they have been added just as items, but i didn't finished their use, they're not usable. Right now you can just drop them and see how good is it.

Anomalies:
Oh, this stuff is so bad, khem.
They are working good, but i think it would lag alot. They are randomly spawned on map and disappearing after some time and spawning on next positions.
ATTENTION: position, specified to spawn anomalies is used as a tile, you have to change the tile number somewhere in "anomaly.spawn" function to have no problems with generation.

Inventory:
Well, you're available to pick up items and drop them. You can select how much you wanna drop at once. Dont be scared when you see "Drop x10" but you have only 7x of selected item, it would drop 7 as well :P.
When you die your items you have in your hand and armour will drop. The inventory items in ur backpack wouldn't be dropped.
When you leave your armour and weapons in hands will be stored into your inventory.
I didn't implement weapons icons in the inventory so you have to drop your weapon on the floor first, then you can hold another weapon. You cannot "swipe" weapons, because i didn't do it :d
You can swipe armours. To unwear armour you have to point your pointer on a player hud in the inventory and click on it.

PDA you recieve messages in PDA about what happening around. You can also say !fm <text> to tell a message in your faction group. PDA is also exists, but as contacts is used players what are visible nearby.(visible on screenshot)

You can type "!items" in chat and see the list. You can type "!i <itemid> <itemsamount>" to spawn items. You should type amount even if you wanna spawn 1 item. Ammo stacks in packs, you can see it in the Items.lua file.