you can also apply for non-o from Canada through evisa. You just have to show either ฿800k in bank or show ฿65k in monthly income. No need for insurance, criminal check or medical certificate
You can still submit the additional docs as long as your application has not been rejected. If it is rejected, you can get a non-o (not OA) while here. You will probably need to use an agent to get a bank account opened and you'll need to deposit 800k before you apply. Even if your evisa is approved AFTER you enter Thailand, you can border bounce to activate it.
By definition, when buying a condo, you are buying the interior walls and floorspace. The building and land are owned by the association. There can be other "common" areas that are part of the association too such as a gym, underground parking, etc you never really own anything with a condo. You buy "rights".