No, all casinos do not use LTD.
There are no rules against re-ordering any chip.
Some LE's have been re-ordered, such as Orleans and NY, NY grand openings.
Other LE's re-ordered were at Boomtown, NV Palace, Golden Nugget in Laughlin and Texas. All I can think of at this time.
At this time, Paul-Son, BJ, and Chipco salesmen are warning casinos about the re-ordering of LE's. If a customer insists, the customer is always right.

There is no fixed number associated with "Limited Edition"