I'm sorry to see that your eggs did not make it and know how disappointing it can be. My opinion on both subjects: First, I don't think the photos show anywhere near enough detail for us to crucify the shipper. The last two batches of eggs I received had each egg wrapped in some papertowel and placed in egg cartons. The cartons were then packed with newspaper around them in a box. Both shipments arrived without a single crack and I had very high hatch rates. I do agree that, due to some dysfunctional postal employees, labelling the box in that manner is asking for trouble. I'm sure that the shipper had only the best intentions and probably does not think the same way those disturbed individuals do. I have owned a mail-order company for 15 years (non-poultry) and know from many experiences just how horribly crushed, beaten and kicked boxes can get in transit. It appears to me that the sides of that box show signs of severe stress that no egg could survive.
Regarding the mixed hatch dates, although it is not something I like to do, I just finished a hatch in that very manner. It is true that hatching is very messy and can lead to a lot of bacterial build-up but I had 100% hatch rate on my later eggs. Again, it is not the best choice but I don't think that it will necessarily be a failure. If it were me, I would candle the existing eggs when the new ones arrive as they should be easy to see if they are developing by that time. Considering how badly shaken up the box was, I am afraid that there may not even be a situation to be concerned about.
Richard