One way that you could do this is by using the Document Grid.

After Skyline has extracted chromatograms and chosen peaks, you can look at the results in the document grid.
You can create a report which has the columns that you are interested in filtering on: "Mass Error PPM" and "Isotope Dot Product".

It sounds like you want to remove all the peaks where the Mass error is above a certain number, or the isotope dot product is below a different number. The Document Grid does not allow you to do "OR" filters, but you can certainly remove all the peaks that you need to in two separate steps.

Once you have the Document Grid displaying all of the rows for the peaks that you want to remove, you can select all the rows and use the "Actions" dropdown at the top of the Document Grid and choose "Remove Precursor Peaks".

If you want to learn more about the Document Grid, you should take a look at the Custom Reports tutorial:
https://skyline.ms/wiki/home/software/Skyline/page.view?name=tutorial_custom_reports

-- Nick