Yes, I'd like to filter out by airspace class, in addition to the altitude filters.
Flying in the South East, with the LTMA above us at 2,500ft, if I have +/-1,000 as my altitude filter (I actually prefer +/-2,000) I see a lot of stuff above me in the Class A that I will never conflict with. It would be helpful to just eliminate them completely.
As for the second suggestion, I want to see my mates. Useful if we're flying together, but perhaps not very close.