My biggest question comes from Alison, I think the MC gives her way to much power/say, without knowing her that well and not really getting answers when it come to what she knows about his grandfather.
The overall plot of "unravel the current equilibrium" could lead to bigger ramifications them what the MC knows / has been told / willing to accept.
Also "creating your own ruling faction" could just be a means for Alison and Elizabeth to take power and push the MC out when it comes to it, (slimier to what Mrs Russell has done.)
Notes: I do know the MC wants nothing to do with it - that doesn't mean he should just dismiss it the way he has.
and I highly doubt the date planed will give us any answers that will solidify her trust.
The first part, yea probably. But I'd say that likely holds true for Alison also. Sure she has a good understanding of how it all works and the various dynamics at play. But that's all in a balance that's only a few decades old at most, since MCs grandfather was exiled. There's once again Five Families ruling. No one likely knows how this will really go, not even those old enough to remember when the council always had Five Families.
I honestly can't see how Alison and Elizabeth could do that. To do what you're thinking Alison and MC would need to get married first of all. Alison is far down the list of future wives, she'd be the fifth wive, minimum. Victoria has already expressed interest in getting involved in the political side of things in the future as one of his wives. Victoria has been somewhat antagonistic to Alison from the start. I genuinely can't see her letting Alison take over. Hell Catherine wouldn't stand for MC getting fucked over like that, her growing feelings for MC aside, MC is her golden ticket for a better life for herself and likely her younger siblings too. And that's just about making MC a puppet. MC openly doesn't trust Elizabeth, so add than on top of everything I mentioned for Alison.
Trying to oust MC like Russell did to his grandfather just doesn't make any sense from the start. Alison and Elizabeth would need at least one of them to be married to MC for them to hold any representative power among the Families. Divorce would strip them of that power, and MC would keep it. Yea Russell is a female Family Head, but her husband is still there alive and well and still her husband.
So yea, long term I see things as being pretty low risk all told.