Do you consider priests in the same position as apostles?  Should we be addressing our local parish priest not as "father" but as "apostle"? 

Being a priest was not Mary's role -- and I suggest our priests are certainly not chosen for sinlessness, our Church wouldn't be in the position it is now if our priests/bishops/etc were sinless.

What do we really know about the apostles, based on the limited documents and traditions that have survived to this day, assuming those writings didn't have some other purpose/message/inspiration or haven't lost or gained something in translation?  In any event, being sinless doesn't appear to have been a precondition for being selected.

Mary Magdalene remains the "apostle to the apostles."  Paul seems to have referred to Junia, a kinswoman, as being among the apostles. The hierarchy has the choice to resume naming women among the servants of God known in this life as priests.