1) A person with no declaration is declaring no action, so suffers the penalty for changing action - attack must be done in deliberate and suffers a -40 penalty.
2) That depends. There are still only three phases in a Hasted person's round. If you consider dropping a weapon an action, then this is four actions and takes more than one round. If dropping the weapon is not counted as a action, however, this can be done. Note, however, that there is no parry during the normal phase (the weapon is dropped, so not used for defense, and the mace is in the process of being "drawn" and so not yet ready even if it was to be used to parry), so the parry only applies to attacks in snap. And at least one of those attacks has to be at less than truly full OB, since drawing a weapon will eat up some activity.
This is to be consistent with rulings that allowed Hasted individuals to change OB/DB split on attacks with the same weapon, where DB from parry applied only until a new attack with a different parry allocation was made.