2 Timothy 2:24-25
I saw this thread and mostly avoided it but came to this conclusion as well. Dispensationalism is not really something that we have to root out within Reformed communions. It exists as sort of a "default" for many American Evangelicals who attend PCA Churches because the PCA is a Church that preaches the Word and stands on Biblical authority. A Baptist friend of mine from Okinawa ended up in our Church here and he wondered why they always found themselves in PCA Churches (not yet convinced of the baptism of their covenant children) and he agreed with me that it was our confidence in the Scriptures to change hearts and not gimmicks, etc that was attractive.To the OP, because it asks specifically about "our" theology, I would have to say FV is the more dangerous because it seeks to alter the meaning and practice of what we confess, whilst dispensationalism is fairly recognisable as being a different theology belonging to a different group. Dispensationalism creates all kinds of troubles in its own environment, but it is not native to the reformed community. FV causes all kinds of troubles in a reformed community because it grows up within the environment, sucking all the nutrients out of the soil, overspreading the garden, and slowly choking the life out of the plants.
I think FV is a danger but I also think it's a fading one. I like the analogy you used about sucking the marrow out of folks. I think it had its apex a decade ago and there are matasized errors that creep up but they tend to group up if they're really committed. The saddest thing for me is to watch a really sweet family whose father was really into patriarchy pretty much abandon the faith. His beautiful daughters and wife have now turned their back on the Lord. I've other friends of Churches I attended where there was a similar pressure of showing how "perfectly" you were raising your kids and practically obsessing about noise from children in Churches who have left Reformed Churches as a result.
I think FV-thinking is always a danger to Reformed people but especially to those with families or those who use their theology as a way to idealize family relationships and the promise that the right kind of parenting will produce the Godly offspring that is otherwise a good goal. It's sort of a sophisticated version of Raising Kids God's Way but it has the allure of faux scholarship and the dressing up the doctrine of wolves in the misapplied ideas of Puritans and other Reformed thinkers.
I don't expect it to survive as a movement much beyond some of its charismatic leaders. Their multi-generational vision will be thrown down and they'll find the world or others to blame leaving many victims in its wake who ought to have received the richness of Reformed theology for wearied souls rather than sucking the life out of them with a cheap alternative.