I don't know the answer to those questions , but I wanted to say, I'm not planning to switch to an open cup on a regular basis for a LONG time. I will work with her to be able to functionally use one, but for general use at home, I see us using straw cups for a long time. It's just easier for the cup to have a cover, IMO. We will probably switch to an open cup at meals first but still use straw cups around the house. Not sure when I might do that, but it's not on my immediate radar.
If I had subsequent kids, I would save any 'nicer' sippies/cups (we wash all the parts in the dishwasher, anyway), but we use the take and toss straw cups most of the time, so I would toss those and replace in the future.