......and peers get immidiatly disconnected before I can fund them.... no idea what I am doing wrong 
Add the following lines to your config (replace DIRECTORY with any location that suits you the best):
Code:
log-file=DIRECTORY/lightning.log
log-level=debug
log-level=debug
Restart your node, try opening a channel again and check the log file if it fails.
.not sure if the exportet HEX file hsm_secret does its job....
It is a backup of your node's on-chain wallet. You should also consider setting up a plugin which will back up your channels.