You are jumping too fast.
1. Flash built-in kernel, then flash the ROM, if you like it (I am sure you will), then move on to try different kernel
2. Find the kernel you want to try, copy the module and flash boot.img just like you did
TWRP 3.0.0-0 is working perfectly with this ROM, just FYR.
Working perfectly with latest ARHD 16.0 :)
After a few days of use, this build is much better than 6.0.1 r3.
Smooth, almost no FC, works well with both ElementX Kernal and Xposed (not 100%, but better than r3)
This is factory image version 6.01, DEODEXED/ODEXED-ROOTED by fhem.
There is no option to flash GAPPS, it is built-in.