Walls and Ceilings - what to do with walls

so we are in the process of pulling the old wood paneling off our master bedroom walls. there is good seetrock underneath that we will eventually paint. heres a couple questions/observations:
1) some of the sheetrock is moldy. would we just need to replace each moldy sheet?
2) some of the joints are not taped/floated, but some are. should i go ahead an sand down the existing stuff first, or tape and float the rest then sand it all at the same time?


thanks for all the help guys.

#1 - it depends on the severity of the mold. If it is just on the surface, it will wash off with a bleach solution. If it is deeper, I'd play it safe and replace it - inspect the wall cavity for mold.

#2 - hard to say without seeing but joint compound will adhere to a clean surface better than a diry one - don't forget to brush off the sanding dust.