Richard,
Have you addressed everything that is associated with rental restrictions?
Percentage/number of units allowed to be rented
Hardship clause
Hardship defined (removes perception of unfairness)
Military clause (could be part of hardship definition)
Rotation of rental privilege (should explain how someone currently renting is informed that they can no longer rent and how someone who wants to rent has a fair opportunity to rent)
Grandfathering of current rentals (if over the percentage)
Grandfathering of current rentals and relationship to rotation of rental privilege
Time limit of owning prior to renting (may prevent investors from purchasing)
Ran the language through your attorney to identify any conflicts or potential issues
Amendments are typically the addition, subtraction or a combination of both.
The amendment should also include the authority and dates of approval of amendments.
Although I'm not in a condominium, not living in PA and it's not a rental restriction, I have attached a sanitized amendment we have adopted to our bylaws. Perhaps you can use it as a guide.
Additionally, here are some link to PA condominium amendments I discovered doing an internet search:
www.sterlingpmi.com/pdf/darlington8thamendment.doc Word document
http://www.mrhenterprise.com/VHCA/document/233170vhca_amendment_to_declaration.pdf pdf document
http://www.daylesford-lake.com/Documents/Capital_Contribution_Amendment/Declaration%20Amendment-Capital%20Improv%20Fee.pdf pdf document
Hope this helps,
Tim