In general, I'm in favor of making the rules as versatile as possible, and alignment restrictions just seem to rule out some character concepts, without being a good balance to game mechanics.
Any real reason why the Paladin class needs to be restricting to Lawful? i.e. Could the restriction be reduced to any Good alignment?
Reading through the Paladin class, the only thing that is actually Lawful-related is in the Code of Conduct and Associates limitations. Could we just drop the Lawful restriction, or make it an optional rule for backwards compatibility?
Barbarians are restricted to not being Lawful. What about say law abiding elite Dwarven Berserkers? Why not remove this restriction?
Similar question, why should a Druid be neutrally aligned? What about Elven Druids in a lawful society - couldn't they be lawful good and still be druidy?
Why should Monks have to be lawful? There's plenty of non-lawful martial arts characters in fiction. One can be a disciplined martial arts fighter without being law abiding. If this was relaxed, the 10th level ability to make unarmed attacks treated as lawful weapons would have to be modified - maybe they could choose between lawful and chaotic?
Thoughts?