God is all knowing amd He sees into the heart of everybody. He knows who truly loves Him and who doesn't. The Unpublished Manuscript mentions that a protestant women who died in a shipwreck went straight to Heaven because she made a perfect act of contrition as she died. Jesus said that the publican who prayed in the Temple was justified while the Pharasee was not.
I believe that God is pleased with the prayers of all those who are truly sincere. He may be more pleased with the prayers of some Protestants than He is with mine. I only hope that I do not become an obstacle to anyone's conversion.
Your post may express your own feelings, which btw, are generous to a fault. However, it's extremely unlikely that God would be pleased with the prayers of a protestant (unless it was to beg forgiveness for holding to protestant errors) because protestants have reduced Christ to being the object of their emotions and by doing this they have denied Him the rightful role of Christ the King and the views of the protestants toward the Blessed Virgin Mary are so repulsive as to be better left unmentioned here.
Sedevacantists will tell you that this or that pope is a heretic because he has expressed heretical views or even written many books that are heretical in nature (see any of BXVI's writings or the jibberish of JPII) but the sedevacantists don't deny the Papacy (which prots do) and then there's all the other issues (perhaps someone else could make a list). The protestant view on the Bible is nearly idol worship with the whole concept of Sola Scriptura.