There are likely to be red flags with Mother Miriam. It seems unlikely that she sees the entirety of the situation. But that doesn't mean that she is not sincere. That my point.
Burke and Schneider have some serious flaws in their view of the problems in the Church - I don't pay much attention to them anymore, and Sean is probably right about the good cop/bad cop, at least when it comes to Burke/Schneider. But I don't think that they are all compromised. I'm sure there are problems with Vigano too. But...he sounds a lot like +ABL in his latest writing, posted on the Non-Possumus blog (at least on first perusal). Vigano's perception of the problem may at least be a little more clear than others. Though I have no idea what his views are on the Old Mass, and older devotions.