So, my thoughts are this. What would have Calvert achieved had he gotten Desmond out of the way?

Would he have become like Mr. House or what would have happened to Point Lookout?

I don't really see Point Lookout as becoming to much of anything. Its only real value is a stopping off point for ships but that is about it, Calvert could of established his little kingdom in the swamps of Point Lookout but a child's pillow fort would have more strategic. So he could build a society there but the only real trade good would be Punga fruit, other than that it would just be Calvert's little play thing.

Apparently he had psychic powers (like communicating with others telepathically) and was planning on using them to take control of Maryland. Whatever that would entail and whatever benefits that would grant.

I had to look the info up because I had entirely forgotten the plot of Point Lookout. It seems I forgot how silly it was as well.

I've never played it, only read about it, but the concept of the "Great Game" looked pretty interesting to me. Also it added some lore in the form of Abbey of the Road and stuff like that.

Point Lookout stands out because that was the only DLC - in fact the only thing about F3 - that NMA praised.

It's a concept that doesn't want to be forgotten. I liked how the survivor hoaxer actually remembered Desmond and the great game.

However, in my opinion, it's a flawed game. It's purpose is questionable, it's main motif revenge. It doesn't hold a place in the greater scheme of things. It's a substory.