I'm not sure about anti cheating measures, and I'm hardly well versed in how memory is handled, but I do think you're overthinking health a little. I haven't tried to get adventureus's ending/bug, but here's how to get unlimited health consistently and without error:
Load up the game and boot up Cheat Engine
Scan for four byte unknown initial value
Expend some air in game, then search for a decreased value
Repeat until you have gotten it down to a few dozen addresses. Most of these will just be continuously decreasing variables, which are best left alone.
In order to whittle it down to a smaller set of addresses, I then went and found a yellow gem, which will put you back up to max health.
Then, after this if you've done it right you should only have a few addresses, just put the DOSBox and the Cheat Engine windows where you can see both and note which address reacts to moving the ball about. That's your health value, in the range of 0 - ~860000000. I suspect the values adventurus found simply corresponded to the sprite of the ball, and perhaps other aesthetic effects.
I've managed to do this without the game freezing, though since memory seems to be randomly reassigned, if the health address changes to one which probably shouldn't be frozen things could go badly. I've had this issue in a lot of other software and I've always dismissed it as being above my skill level.
Now, this health value is for the level you found it on, only. For each level, you'll have to repeat the above process in order to get infinite health again. However, they stay the same, so if you quit out of a level and come back, it'll still be the same address.
I think the yellow gem just resets you to maximum health (or after freezing the address, tries to) so I doubt you have to worry about dying from over inflation here. However, the game does have instakills which will work regardless of infinite health. One of them is this spike thing: , and the other is the coloured gate: . This is particularly important on the last level which contains teleporter traps including these, so try to take unknown teleporters slowly as you keep your momentum going through them. For many parts of the game, I would recommend holding the air brake key (default z) so you will only move while holding one of the movement keys.
As for actually playing the game, I don't think health is the only factor one has to worry about. As was said in the video, the game is a slog, and you are meant to get through it in one sitting as it has no save states. The game's instructions (Press i on menu) are worth the read:
At the end of the third paragraph here, Sean Puckett states that there is no ending for Helious 2. Ross brought this up in the video, and went on to explain it might secretly notify the aliens about the game's completion. I am a skeptic, but at any rate I don't have much time on my hands, so I would like to see what will happen after beating every level. In order to help with that, it would be best for someone to beat it and share a save state here.
The official DOSBox doesn't have support for Save States like you might see in other emulators, but there is a modified version of it called DOSBox SVN-Daum which allows saving by a simple hotkey. You can download it here (E: Official Website, can't believe I missed that one), and read a forum thread about it here.
I found the documentation on it a little inconsistent so here are some instructions for use of the mod:-
This is what I've learnt so far. I'm not convinced there will be an ending but for those of you who are more dedicated than me, good luck, and please share it before your abduction! If you manage to get part way through it but lose hope, share your save anyway! I'm sure someone will pick it up.
E: The default health is 655294464. This should make finding it a lot easier.