Do you use it or its just not worth it because u cant use a lot of the players stats with a small sample?

I guess this filter wouldn't be overly useful as it doesn't really matter what the blind levels are, more what their stack size is in relation to the blinds.

This.

Well it miiight be usefull over a huge samplesize. This brings me to another question: is it possible to make PT only show certain stats in the HUD if we have a certain sample size of the opponent?

No but u can just check the sample size and decide if its big enough or not.

HEM has that feature Tonitto...I'd bet PT does as well.