Tried to make my own modded EBOOT

Those sound like the exact correct options. 1 to decrypt, 2 to encrypt as non-npdrm eboot. I'm used to doing nothing but dex eboots at this point so I likely avoid a ton of errors that others would encounter so I'm a little lost on the black screen. I previously got black screens in the game by putting certain codes in bad places that when the game started or was in the process of booting. I assumed the zeros were unused space when the game used them for game data installation related things and possibly other things. Does it happen to just that 1 exact code? It's always possible it could be a firmware encryption related thing even though I never deal with that stuff any more.

If other codes work and just that one fails, then I know there's a problem with the code and can actually try troubleshooting it and fixing it by moving it to another location, but otherwise 99% of the time one of my codes isn't working for somebody it's usually them messing something up even though this sounds like a possibly legit problem at this point.

The problem is not in your code. It's on my side, but i can't find out why yet.
The thing i notice is that original EBOOT is 7,8mb, but the modded one is 3,6mb. Doesn't matter if i add 1 or 5 cheats.
I guess this is not normal to happen.
Also i tried just to decrypt and encrypt the eboot without adding any cheats and again after the encryption it became 3,6mb, but this time the game runs fine. No black screen, no freeze. So i guess im adding the cheats the wrong way...
Let's say i want to add cheat:
Electricity Never Decreases
0 00124598 D1840008
Code:
SET OGP=C0040008EC01002AC1840004FF806800ED606028419C0008FDAB032ED1A40008
SET COP=C0040008EC01002AC1840004FF806800ED606028419C0008FDAB032ED1840008

I tried with HxD to find OGP and repace it with COP, then save eboot.elf and encrypt. The game load and freeze right after showing Cole. And i had to hard reboot the ps3.
I also tried to replace OGP with COP with RivalGamer_ELF_Cheater it says success, but to no avail. Again freeze.
I don't know what to do with 0 00124598 D1840008 this part. Do i have to replace it together with COP on HxD or any other way?
I tried with aldostools cheat editor to add cheats to eboot.elf, still freeze

For Infinity Health why there are so many codes:
Health Never Decreases
0 00564ED0 800100F4
0 00564ED4 3D600012
0 00564ED8 616B808C
0 00564EDC 48000020
0 00564EFC 7F8B0040
0 00564F00 409E0008
0 00564F04 C3FD0750
0 00564F08 482AEDB6
0 002AEDB0 48564ED2
Code:
SET OGP=000000000000000000000000000000002C00000100090003000000000000000000564AFC00564C200075FBC000000000000000000000000000000000
SET COP=800100F43D600012616B808C480000202C00000100090003000000000000000000564AFC00564C200075FBC07F8B0040409E0008C3FD0750482AEDB6
SET OGP=60000000D3FD07545463063E2F830000419E01203BA00000FF9DF000409C00E4
SET COP=48564ED2D3FD07545463063E2F830000419E01203BA00000FF9DF000409C00E4

Which of them i have to use? The first OGP>COP or the second? And what abut this kind of codes: 0 00564ED4 3D600012? How do i add them and where?
I know that's a lot questions, but i want to learn to make my own cheat eboot. Sorry for my english.

The Electricity code should definitely not cause you any problems, it does not even involve a custom routine out in the middle of nowhere. That should be 100% safe to use. As for the addresses thing like "0 00564ED4 3D600012", the 2nd part, 00564ED4, is the address in live PS3 memory that gets modified. For eboot modification in HxD.exe or anything else, you would subtract -10000 from it and then overwrite whatever is there with the last part. So with that, you would do 00564ED4 - 10000 making 00554ED4. You'd go to 00554ED4 in HxD.exe and overwrite the value there with 3D600012 and that would be the code.

The size changing doesn't usually matter. scetool or whatever has the option to compress elf files, so seeing them decrease or increase in size affects nothing. The only problem is that with your non-dex ways, there can be some very picky details for encrypting the eboot back to normal again. If you are able to decrypt the eboot and encrypt it without modifications, and it works, then that would suggest either the codes are broken or they are somehow input incorrectly. There is no way the electricity code can crash your game, that's a sign of user error if it is.

I will try to add the 0 00124598 D1840008 code now. Do i have to add OGP and COP of the first way is enough?

The address method and OGP/COP will get you the same result in HxD.
Did you have any luck with codes that aren't that health code?