Hello and sorry for your bad experience,
BUT: I am almost certain that it's not about my ROM, but either you might have an hardware issue with your P6000 Pro, or it's the plain fact that you seem to be using an awful lot of (5 or more) low-level system applications at the same time which heavily interfere with each other and most probably are the cause of all your troubles.
The only one of all the low-level apps you listed that I use as well is Magisk in order to make my device Safety.Net compliant. I can confirm that any recent combo of Magisk Manager and Magisk works completely fine on the P6000 Pro with my ROM.
I think that both Kernel Adiutor and the Doze mode have been designed for Android versions later than Lollipop, so I doubt that using them makes any sense.
In order to confirm (or exclude, but I'm rather sure they are the root cause) your bunch of system applications as the source of the issues that you are seeing, can you please reinstall nothing but my plain ROM and then see whether a) the phone and the phone status line works properly (even for roaming - I put a lot of effort into it to make this work, as this was broken with early CM12.1 for dual SIM phones as well as with the MTK code contained in Deepflex's build) and b) you get no battery drain at all (you may want to confirm this by using Better Battery Stats [which might be as old as the Android 5.1, but at least works properly on it] installed as an APK).
Once you have confirmed that it's not my ROM to be blamed for all your issues, please move forward and add gapps on a subsequent installation attempt, and only then and only very carefully, one by one, any other low-level system apps. I personally don't need any other system level apps other than Magisk with the Magisk Hide Props Config module and Busybox, Better Battery Stats and possibly an app that confirms that Safety.Net returns proper values.
If you stay with a decent set of applications that make sense to be installed on a 2015 Lollipop phone, you should get a good user experience, but you must not expect to be able to run the most recent system-level apps on such an old device...
Edit: I forgot to say that with ~ 30 apps installed, I don't have any battery drain issues at all, and my battery typically lasts for between 12-48 hours, depending on how much I use apps/the screen. Making phone calls by far consumes less power than e.g. video playback or other permanent use of the screen. And yes, Better Battery Stats confirms that my phone is in "deep sleep" mode for most of the time when the screen is off.
Ah, and please note that - as clearly stated in the README - it's not "my" kernel, as "my" build only consists of combining other people's work to form a current ASB-level build for the P6000 pro:
- visi0nary's kernel (I am almost certain that I am using the latest available source for this type of device which includes all needed kernel driver modules)
- Deepflex's original build for the P6000 Pro in terms of his "device " and "vendor" tree
- cm12-amami as the most current build of CM 12.1 making it possible to provide current ASB levels
- the latest stock ROM to update the binaries for "device" and "vendor" tree
BTW: Stay tuned - depending on my free time, I plan to provide a new build of my ROM based on ASB level 2020-01-05, i.e. the current January 2020 version of cm12-amami, and hope to have this available until the end of January...
Hope this helps & best regards
---------- Post added at 11:28 PM ---------- Previous post was at 10:55 PM ----------
Another addition: You say
"very fast draining - around 10-12h with 2-3h SOT (and because there is no no deep sleep...)"
But please keep in mind that the battery included in this old device only has (IIRC) 2700 mAh, which is quite low compared to current devices, so a screen-on-time of 2-3 hours is not too bad, is it?
It is at least sufficient to watch a full 90 minutes football match...
Most probably, I also don't have much more than 2-3 hours screen-on-time, but - as can be confirmed from the logcat logs as well as using BetterBatteryStats, this is not due to any battery draining app (other than the screen).
If the phone is in standby mode with screen off all the time, IIRC, BetterBatteryStats says that it loses 1,2% of its load per hour, which would mean that in theory, you should be able to get ~80 hours of standby only.