So, after a short vacation, i finally got back to printing. At first i have to say, that my problems are SOLVED!

I bought some Kapton-Tape and it led to better adhesion, but not to a point, where printing was reliable.
So i disgarded this idea and went back to covering my printbed in ABS-Slush.

If i do a quite dense mixture, it works VERY well! 100% success-rate after i got the mixing correct.
Before the print, the bed looks very messy because of the Slush, but the prints turn out very well.

So, in short, my final configuration is the stock glass-plate covered in ABS-Slush.

Thanks for the tips from all you guys :-)

@milcent:
Since you posted also in the other thread, i will just answer here.
Link: http://3dprintboard.com/showthread.p...ot-solid/page2

Like joop in the other thread said.. there is no real support from HK (which they have said from the beginning, i think).
The printer, to me, is just a package of parts, where you know that everything fits together.. but you have to figure out settings etc. by yourself.
You have to defenetly build it yourself and you have to invest a fairly big amount of time setting it up right.

But, as joop said, the parts all are readly available from china.
I personally would not send it back to HK. But i also like to figure out stuff myself. So if troubleshooting is not your thing, sending it back might be a decent option.

In regards to further failures of the printer:
- The 5V regulator still works fine for me. No issues at all.
- I have used an extruder-Temp of 252 °C for over 20h now and the extruder seems to hold strong.
- I also had to change the steps to about 85.

This, in my opinion, shows how much the printer differs from user to user.
You have to figure out something by yourself!

But despite all my problems, i am happy i bought this printer.
It is not a ready-to-print package, but in this way, you learn how your machine works!