Brand new z3 running 4.4.4

[Herts_JoaTMoN]

I have been given a brand new z3 from a friend who found one in a drawer at work. Build 23.0.A.2.93. Kernel Version 3.4.0
I've not had an android device since about 2012 so am out of the loop. Been reading up on here a bit to see what I should do and am looking for a little advice to help speed up the process.
Should i update the phone to the latest stock everything prior to rooting or should I go with an earlier version?
I'd like to run nougat on it. Looks like lineage is the most regularly updated version so I will most likely go with that. What is the best kernel to use though? I like to mess about with voltage and clock speeds etc.
and links to appropriate threads would be appreciated. My friend has made me nervous about bricking the phone as he seemed to indicate that sony phones are harder to root than most

Any help would be appreciated

 

[Azhar_Fahry]

- Ok. im running lienageos 15.0 right now like 3 days. kernel is jsut stock i guess , no overclocking etc, 2.5 ghz, smooth , snappy perfomance and no bugs, but battery drain just a bit, but its normal. s
Link : https://forum.xda-developers.com/z3/orig-development/rom-lineageos-14-1-t3690988

-Root ur phone by unlocking ur bootloader with flashtool , and flash recovery with flashtool too, and download the rom that u want, but first u need to update ur phone to the latest release , use Xperia
Companion , and click Software Update, just follow the instruction or u can update directly from ur phone settings.
Flashtool : http://www.flashtool.net/downloads_windows.php (don't forget to replace the x10flasher.jar)
TWRP : https://forum.xda-developers.com/z3/general/recovery-root-mm-575-291-lb-t3435214 (i follow that tutorial and it worked for me)

i know its already late , but maybe other people can find this useful. just wanted to help

 

[TjNiko]

last real good kernel is the ones from shadowelite for MM(6.0) its a full advanced kernel and u can cotroll the OC and voltage along with other awesome features. bad that after that no more costume kernels appeared, only stock ones in LOS with only basic features. but Android O gets much love at the moment.