cringes a little
If we say we do not know whether the saints are alive or dead, does that not bring us awfully close to believeing in no after life? I have no trouble with asking the prayers of the saints, and yes, they do save us by their prayers. The equivelent would be asking a brother or sister in Christ here on earth to pray for us. The Saints of God in Heaven, the Church Triumphant, is able to offer prayer to the Lord more efficaciously by reason of their position in the Glory of God. Indeed, they more alive than us on earth, because they have put off the corruption of the body and its passions.
When we say "Most Holy Theotokos, save us!" we mean that she who has bourne Christ Our Saviour, by her participation, has and does save us, both by her willingness to bear God to the world, and by her intercession before the throne.
I call to mind the wedding at Cana, where Our Lady asks Jesus to do something because they had run out of wine. And though He said, "It is not my time for miracles," He performed a miracle, at His mother's request, turning the water into wine. He did not refuse her. If we ask the prayers of the Theotokos, who intercedes in the presence of Christ our God, I believe (accept as fact) that Our Lord and Saviour Jesus Christ answers Our Lady's prayers for us, for she loves mankind, and is our Mother, too.