The unlawful_territory modifier (reduced manpower & tax, incr revolt risk) does not go away until the province cores, regardless of any other changes. You won't have that if you're the Emperor though; you may get it after you lose the title if you don't abolish the Empire quickly.
The occupied_imperial modifier (+ infamy, - prestige) might go away if the Empire is abolished.
This. There are two types of unlawful territory.
One is the province modifier from denying "Formal Request"(event 6007, RandomProvinceEvents.txt), which will fire on any non-core province that's still part of the HRE, if you're not an emperor, and when neither of you are at war. This can ONLY be taken off by its counter event with 24 MTTH that fires when the province is cored.
The other is the infamy increase and prestige loss for every un-cored HRE province you own, and is applied to everyone including the emperor. This one will go away as soon as a province is cored or when it's left the HRE.
Do note that if a province already has the modifier and then given to the emperor, the modifier will still stay there until it's cored by the emperor.
This has probably been answered before, but,
Can a revolt result in the birth of a new Nation? Austria has an island community within my borders w/o military access. It is occupied, but will it stay that way forever or eventually become a new Nation?
Depends on the rebel and the province. Given the correct rebel type and with 3~10 years of rebel occupation, the game will try to find a nation that fits the defection criteria and give the province to him. If no one fits the criteria, it'll create a new nation that has (or should have if Promote Cultural Unity was used) a core on that province.
You should probably read through
http://www.paradoxian.org/eu3wiki/Rebel for which type of rebel will defect it to you.
Thanks! This is news to me. I tested this out a couple of different ways and it seems to work only for provinces in the HRE. Is that true?
In answer to Dankysh's question, there is no PU between Burgundy / Brittany and Bohemia is the Emperor.
I stand corrected. I probably confused it with walking through my vassal, PU, or HRE member without MA/alliance.