looking for a good 3d printer

[A_Camera]

Yes lots of failures but I guess its a learning curve. I had bed leveling issues and poor prints with layer shift, since found out that the 2 or the 3 screws holding the main x-y carriage where missing and the 3rd was loose.

Too bad... never the less, at that price I'd expect that something needs to be fixed. Glad you managed to fix those small and simple things. Levelling issues are not difficult to fix but depending on the results you expect and the instruments you have to help you, can take time. Anyway, regardless if it is a CNC or a 3D printer, I think that spending time on levelling is beneficial in the long terms.

tightening them has solved the layer shift but Im still getting 1mm variation on the bed calibration. guys on the forum think it is the micro switch but it seems to work fine when I tested it with a meter.

Not good. On the other hand, 1mm variation should be easy to reduce considerably. If you have an instrument to measure than you could see if the problem is mechanical or electrical. The mechanical variation takes some time to remove or reduce, but normally should not be too difficult.

I think it will be a good machine but needs a few tweeks and lots of wear, the previous owners must have used it a lot.

biggest issues that i missed when researching are the bowden extruder and being stuck with the wanhao maker slicer program. (firm ware upgrades to 3d partry but not brave enough to try)

What do you mean is the issue with the bowden extruder? The printer I am planning to build is planned to have bowden type of extruder, so I'd be interested if there is an issue I did not think about.