From Here. 29. Is there an upkeep cost on the land or buildings?... Stronghold parcels do not have a direct tax. Instead, they apply a multiplier to the building(s) placed on that land. ...
So, presumably, they will reduce (or eliminate) the upkeep you must pay for buildings on the parcels. Or something else. This one isn't entirely clear you're right.
They don't exist yet! So noone knows! Given we know Parcels are like Tetris blocks, it's probably a good guess to say that most Parcels will be around 4 cells. Each Cell is 5 lots x 5 lots, and each lot is 8 metres x 8 metres. (From the same FAQ as the previous question)
I don't think it was stated anywhere that tax-free parcels were KS-exclusive. Kickstarter packages get a much better deal on them, however! I can't find a statement anywhere if they are only available during development though.
Cause you get a better deal.
B-but you do?
Yes? Why wouldn't you be able to? You can drop parcels and stuff in any kingdom you have permissions for.