I'm looking for an interesting type of added challenge to the game. If there's any simple way to hide the enemies hud, such as exclamation marks and health, that would be awesome, because without being able to read off an enemy actors health, you have no indication other than their movement and appearance of what their physical state and threat level is like. It makes the enemy stand a better chance against you. The health bars as they are make every actor stand out, showing you where they are, drawing your attention, followed by your gunfire.

Without health bars they would become subtle and sneaky. You'd have to be much more cautious with what you do. It causes you to have to stop and evaluate situations more thouroughly. With healthbars you make no mistakes, but if you happen to missjudge an image of a solider lying covered in blood for a corpse, when infact he was alive with no health bar, it might just cost you your life. Tredding through the buildup of rubble you might just step on a droid that wasnt quite dead, and he digs you into oblivion. Or that soldier you assumed was dead after putting him to the ground with your shotgun might just get back up again and put a few rounds into you as payback. This simple edit could make the game alot more challenging without actually altering it much at all.

You can see what I mean in some ways such as fighting an actor with a team value 0, or if looking across the loop point of a map with a long range gun they dissapear due to a visual glitch. Even hiding their aiming reticule would help, as your only warning of when to take cover is seeing the actor raise his gun, which is alot more realistic, and challenging.

team 0 is your team, team -1 has no HUD.
you should also be able to edit some of the base.rte HUD files to remove all the green team HUD.
to remove health indicators for any actor, make its charheight = some rediculous number.
♥♥♥♥ explaining, im going to bed. just wanted to clear up the team numbers thing.

Easiest and most balanced way of doing this is raising the CharHeight of all default actors to at least 10,000.

999999 will make absolutely sure you don't see it.

This will also make your own actor's health impossible to see; hence the balance.