lon,
you definitely could use "required" with probably not too much downside... the only area I might not use "required" would be for something like password or username fields where I would want to ensure that it was absolutely an alphanumeric entry with no spaces... anything else, though, like names or other arbitrary input that cannot be validated someway else (i.e. email, numbers, etc.), I would use "required" instead.
Cheers,
Brian