I found bumpkeying to be really fairly easy, but as an illegal form of entry, well, It kinda makes a lot of noise in a door compared to picking. But I guess It's less noise than a brick crashing through the window...
Enough said about that, Anyway...
I found that .25 mm to .50 mm was a right amount to take off. And for the cuts, I just deepened them an ever so small amount. Keys work like a charm now. Just gotta heal that BK thumb (Bump Key Thumb...new type of injury, LOL).
Olcaytug, what part of Turkey are you in? I am half-Turkish and was born in Izmir, Turkey...decided to take up the Turkish language this year too...trying to plug along.

Getting better though.