For USPS shipping rules, we always obtain the generic Package rate from USPS.gov, regardless of the package type selected in the product's Shipping Options (i.e., selecting Large Envelope obtains the same rates as selecting any Box or Tube package type). The current USPS Package rates for a 1 oz. parcel to Sweden are 6.55 for First Class or 38.00 for Priority (the 23.95 rate is only for Priority Flat Rate containers, which we do not obtain rates for).
We don't have any way to change a product's package type based on order quantity, but this doesn't actually matter for live rate lookups, as we always obtain the Package rate regardless of package type selected. Do at least make sure you specify an accurate per-unit Weight for each product, as well as an empty Weight for the package types you're using in Seller Admin > Cart Shipping Settings.
BTW, I notice you have USPS Priority and Cheapest rules for Country:All Countries, but you only have a USPS Priority rule for Country:United States, which would override the All Countries rules when the buyer selects United States in their cart; therefore, US buyers would not be offered a First Class (Cheapest) rate when available. If you want to offer US buyers a First Class rate as well as Priority, simply delete your rule for Country:US, so the All Countries rule would apply to US buyers as well.
