Let's get some more Taxing levels out of the way.
Taxing 4: builders, bashers, miners (100%)
Taxing 5: builders, bashers, diggers (100%)
Taxing 6: bashers, diggers (100%) -- obviously I'm not able to verify this for myself but it's fairly well-known that such a solution exists in the DOS version
Taxing 7 I won't answer since
there exist solutions that don't use all five skills, but that post doesn't state whether it's possible to do without the climber
and blocker.
Taxing 8 is obvious: builders, bashers (100%)
Taxing 11: builders, diggers (100%)
Taxing 12: builders, bashers, diggers (100%)
Taxing 13: climbers, blockers, builders, bashers, miners
Taxing 14: builders, bashers, diggers (100%)