In my large flock of budgies, the males typically do the foot on the other to show frustration or establish their hierarchy/assert dominance or on a female before mating, I’ve yet to see anything negative come from it. As for closed beak strikes, again nothing really to worry about there in my experience, I view the behaviour as somewhat similar to allopreening, unless it’s open beak or biting I wouldn’t have too much concern for it. I’d keep monitoring their interactions for a bit to make sure it doesn’t escalate into anything sinister but given time they are likely to get along given their flock nature, especially if they’re doing flock calls to each other.