Hictop prusa i3 3dp-11 firmware update(no save fnc on lcd?) and aut.lvl.Z etc probl.

[Warmaster]

Hey
I bought this http://www.ebay.co.uk/itm/HICTOP-Aut...3D141913024926
sorry for horrible link
HICTOP Auto Level Calibration Prusa I3 Reprap 3D Printer MK8 24V Power Supply


So I guess it is 3dp-11 with autolevel sensor for Z-axis.
Few problems. First there is not save option on LCD and guess what? the seller does not answer me nor does hictop. I have adjusted the autolevel sensor sn04-n many times but since I dont have a good guide I have tried and error. I cannot chance the Z axis offset because there is not save function so I guess they just have this old board lying around and did not upgrade it to support all features.

Ok tonight after like week of losing my nerves on this infernal machine, it decides to print me a tiny robot(yay!) but guess what happened when I tried again?
It tried to pierce the bed and draw lines on it until I pulled a plug. I'm starting to think that the autolevel sensor is useless. I am not sure but doesn't it run on 5v on this machine? and on sensor 6v is lowest operating voltage. that might make the sensor read wrong from time to time, dont you think?
Also I thought maybe the aluminium warm bed might change shape and sensor goes wild or something but that is quite a big no I think. 50celsius aluminium should not expand that lot in thickness?

So question really is, can I use this guide to upgrade the firmware and does that 24v version make some difference?
Machine is quite ok built. I have checked everything twice or more times.

THESE BELOW KINDA ANSWERED

I list questions here for easier answer.
1) can I use the newest marlin? I THINK I CAN, JUST NEED HELP WITH RIGHT SETTINGS
2) Should I throw the autolevel sensor out of window and just use end-stop? DID THIS ALREADY
2.5) or does anyone else have advice for that sensor sn04-n. How lot does it actually get voltage? I could not measure cus I was not sure how. GETS APPROX 5V AND MIN IS 6V, CAUSES ACCURACY PROBLEMS?
3) any good first calibration guide for this machine? I have used a paper to roughly adjust the bed so theres tiny friction between nozzle and paper. DOING THIS LIKE ALL ELSE
4) please tell if something should be upgraded instantly or suggestions so I would not waste more time trying to make this work with not proper parts. RESEARCHING, BEARINGS ARE BAD AND SLIDERS WOBBLY
5)is glass a good idea to put over that aluminium bed? (well not using that before I fix the autolevel or stop) NOT GOOD IDEA WITH SN04-N BECAUSE IT CANT READ SO FAR AND GOOD
6)if I remember correct, you cannot get the original rom from the board to computer? I mean "download" I have played with arduinos but now my memory tricks me. POSSIBLE BUT THE VERY ORIGINAL I ALREADY FLASHED OVER

if any kind soul could answer soonish. Im going home in about 4 hours and would love to start making this work again.