Alas, we can't tell without knowing exactly what those low, medium or high risk issues are. And you didn't tell, so how could we know.
So all I can say is to repeat our general advice about registry cleaners: DON'T USE THEM..
I run Advanced System Care and under Registry Fix it found 247 problems to be cleaned. All of them except 70 entries, are of high and medium risk.
Does anyone have an idea if it is safe to go ahead and repair these problems through the repair procedure of ASC or I better not trust it and leave things as they are?
Needless to say, since I am a layman, I am not able to judge the importance of those problems and decide what to fix and what not.