Well, now 2013 after the Lv cap raised to 99 and two new jobs here is my opinion.
Kickstarter- In order for Squareenix to invest time to properly port this to a single player they would need to sit down and actually look at the cost to port this. From my coding experience if they had a team of 5 programmers (because that is all they would need). At the level company they would each make.....almost 10k for the project. Anyways getting off track. Kickstarter is a great way for them to take their assesment of cost post it and see if they can sell pre-orders. Kickstarter is a win win. We as consumers would win because we get the FFXI story experience even when they decide to pull the plug on the servers and game. They win because they didn't even have to spend a single dime to make the game. Plus the fact that Square Enix is doing a Final Fantasy Kickstarter is enough advertisment.
NPC - Really replace players with Story NPC's eg: Lion, Zied, Ironshield etc. Imagine you could do quest to unlock certain NPC's in the game not only your custom NPC fellow but one from the Missions and quests. I can work.
Monsters- Most of the game you can solo now with your fellow thanks to the Fields of Valor. But obviously monsters like Ultima and massive bosses like that require you to get in 18 man parties then they obviously need tweaking. simple math corrections.
If they did a kickstarter for this I could see it like this :
20$ donation gets you alpha access to what is going on in development and a t-shirt that has something to do with Final Fantasy XI.
60$ donation would be your preorder and all same gifts below 60$.
(something along those lines.) I would love to see a strech goal like bring the game to Linux and Mac to reach a even bigger audience.