Stan Prevost wrote:
Then
another controller wouldn't let me descend in time (while I was still VFR On
Top), I wound up cancelling IFR and circling down to the airport.

Wouldn't let you descend? It's not his call. You tell him you're
descending, if you choose to tell him at all.



From your post, I learn that I should report OTP as soon as I am OTP and can
remain so, even if I have not reached the "report reaching" altitude.

The report reaching altitude is usually the top of that controllers
airspace. That way he is protected in case you don't break out. Here
we don't usually have clouds so you're on top while taxiing out.


Then
I should be cleared to just Maintain VFR On Top, and I can continue to climb
to my desired altitude. Is that right?

Right. As you break out just say "N123 is on Top at this time" and keep
right on climbing to whatever altitude you wanted.



It's been too long to remember the details, but once I left our local
airport in Class C and the controller would not clear me for OTP, or gave me
OTP below 10000, can't remember now. His reason had something to do with
he didn't own the airspace above 10000. Does that mean the controller must
restrict my clearance to something that will cause me to be contained within
his airspace?\

Yes. If there are no clouds just tell the ground controller or the
tower controller that you are on top at this time.