the only reason i ask is because it may add another level of protection/validation and in the one in a million chance that someone else winds up with your private key they won't be able to use it. would this add extra security to the protocol?
The chance that someone manages to guess your private key is close to zero. It is more likely that 4
definite people get independently struck by lightning tomorrow, so there's not really a problem here.
And if we assume that the issue you're seeing here was an actual issue (in fact it isn't), then your idea would be a non-solution because an attacker could still try to guess your password just as he can try to guess your key.