Fitting property for armor and polymorph, non-humanoid

[Akari Sayuri "Tiger Lily"]

From the Giant Hunter's Handbook:

Fitting: A fitting shield or suit of armor instantly shrinks or grows to suit the size of any creature that picks it up unless it is currently worn by another creature. It reverts to its original size 1 round after it leaves that creature’s possession.

Question 1: Presumably, this only changes size, but not form of armor? So you could not have it reshape from humanoid to non-humanoid and wear the same piece of armor in both a base and a wild-shaped form?

Question 2: When polymorphing, can you choose not to meld a piece of equipment and continue wearing it if it can resize to continue fitting you? This could apply if I am wrong about 1, but I am also curious in the case of something like a Wondrous Item.

Question 3: Assuming I am right about 1, would it be possible to get, say, a Small Fitting armor, shapeshift into a Tiny form (ie Fox Shape), then jump into the armor and have it fit to me without needing someone else to help me put it on?

Question 4: Either following 3 or following a party member helping me fit into my itty bitty armor, what happens if I shapeshift back out into a medium form - do I shunt out, or do I need to keep a whole bag of holding of spares handy?