I finally have been starting to get some constant activity with adsense but some seem to be rather low paying. Is it a good idea to try and find out which those are and filter them or should I just leave them for now?
You can filter them, but at some point you reach your filter maximum and those ads just keep on showing. It is a good idea to filter what you believe to be the very worst offenders. Then test (I use a tracking script) to see that it is actually making a difference.
just email google and suggest to extend that damn competitive filter to at least 2000 sites..that should be enough for some time