Regarding 2. I can tell you what we did (July 2019). First we got a car from Rincon Del Socorro (they arranged it for us) in the afternoon and arrived in Posadas in the evening. I think it took somewhere between 3 and 5 hours (don't remember exactly but RDS can probably tell you about that). Most of them were in the park so there were som animals to spot every now and then on the way. Next morning we took a bus 6.30 to Puerto Iguacu (arrived at 12 noon so 5½ hours). Booking the bus was easy (we used Busbud to book it online), and it was fairly comfortable. So it does take some time but we didn't feel that is was that bad.

We just arrived in Ivuazu from Rincon. All in one day. If you are roadtrippers you can do it. it was an 8/9 hour drive but well worth it.

Thank you for all of the answers.

I will send an e-mail to Rincón del Socorro's e-mail address. TripAdvisor will not let me post my e-mail address here.

Thank you Razmuz for the valuable information.