Not really, no. The limits have nothing to do with the League of Nations. Only the naval-treaty limitations are... treaty bound, and you can refuse to sign such a treaty.No, no - the limits should only be taking effect if you're in the League of Nations, iirc. If you refuse to join, then you should have free reign over your forces.
Most major nations in the interwar times were democracies. They had a very hard time maintaining or even financing their armies as they historically were (except for Japan). That's why there is a limitation. Else someone will stockpile tac-bombers as belgium during the interwar era and then steamroll-bomb their 20-division army through germany in 1940. Feel free to deactivate those events by deleting them from the event files, though.