Something that would not mind your needles and cones and dryness is creeping periwinkle, although it don't know that it would flourish far into the sunniest areas. It has a lovely waxy deep green leaf and provides a lovely blue carpet of flowers in the spring. It stays almost evergreen under the snow.

As far as thugs go, the only two I know of are Sundrops and Obedient Plant. And both are thugs. Good luck getting rid of them if you change your mind. On the bright side, both are beautiful when they are flowering. Carmellia

goutweed, also called false lamium. it's a thug indeed, but it's got striped leaves, and will only need to be 'watered in' though the heat of the summer the first year- after that, it's indestructable.

Lily of the valley might also thrive there (they like pine and hemlock needles)

and lilirope is the 'classic' dry shade plant, but I think it's kind of dull looking, and needs to be bought.

Gro-low sumac is very drought tolerant and is great on slopes. Probably would prefer more sun, but would do well from what I have seen. Great fall color also. Double check whether it is hardy in your zone, but I believe it is. Good luck.