I think a Florent marriage with the Tyrells would also cause some interesting things in the Reach. Some Reach lords might still see the Florents as traitors after all, for supporting Stannis. And harboring red priests. 

[@Abefroeman]For Lord Lorimer, I think that'd be a neat twist. There is a peaceful path here for the Reynes to rejoin the realm. They want their lands back, not to overthrow House Lannister, so Lord Lorimer might be able to help smooth something out. 

For Aerion, that sounds like a good progression for him. I think they could offer Aerion a castle, perhaps the Aegonfort (the old land of Aegon Blackfyre) and he could seek a marriage as well. I think they can also allow him to keep his egg, and it can even hatch. But the Throne might try to pressure him to consider calling himself a Targaryen and not a member of a separate house, in order to avoid another Blackfyre situation. He could definitely seek a marriage as well. 

Big backstory changes are that Sansa is now Lady of Winterfell and she's no longer married to Tyrion, though both are on the small council. Tom is now the son of Tyrion and some other noblewoman. Young Griff is also no longer married to Princess Arianne, so his dragon rider kids are legit Targs. Might change the spouses for Princess Daenyra and Viserys as well. This frees up more space for setting up marriage alliances, and potential for driving conflicts in between the noble families. 

Tom is still married to Alerie however.