I'm really really really sorry for give you this answer so late.
I just forgot it and I was so much traveling last time. I will answer to you now within 24 hours !
At first of all, thank you for your amazing help, really. Without ...
Just take the MiniGapps HDPI_miniGAPPS-7.1.1-20170108-tb-signed.zip or HDPI_miniGAPPS-7.1-20161031-tb-signed.zip at https://androidfilehost.com/?fid=745425885120698951 if you really want to install GAPPS.
But be careful: Better flash them DIRECTL...
That is totally okay. There cannot happen any more cause you still didn't flash the ROM yet.
You just have to go the next step: Accessing the system recovery and flashing the ROM (whole zip file) itself. For that volume up or down at the beginning...
Thank VERY much!!
I will try both ways now...
Just take this ROM: https://basketbuild.com/devs/AdrianDC/LegacyXperia/haida .
The zip file contains the LX kernel (boot.img) including the TWRP recovery.
Install instructions you will find here: https://github.com/LegacyXperia/Wiki/wiki/Installin...