I would second that the SSPV has these cultish practices. While I have never been questioned by the priests about the sacraments, they, from the pulpit, say not to come to the sacraments if you go to Thuc-line priests or even priests that associate with Thuc-line priests, amongst other things.
As for Fr Collins, I do know him and he is very knowledgeable and a humble, holy priest who is doing what he can for the souls that God puts in his path. He knows many other priests and is friendly with the CMRI.
If you assist at his Mass, you will be in good hands.