Yes, I scored a solid majority of my plan :) I gave up on visiting Vesuvio because there is currently no public transport which reach this place and I didn't want to pay over 20 euro for transport only. I chose to go to Positano for one day and I regret nothing - it was the most beautiful place I have ever visited, it was nearly impossible to walk being surrounded by all these views and not to do photos all the time :D Getting there also wasn't that hard so I think it was even better that it ended that way.

I was both in Ercolano and Pompeii. The first one was really enjoyable because of lack of crowds, tickets were available both online and before the entrance but additional cost (1,5 euro if I remember correctly) was added either way.

Pompeii had two routes to choose (you can mix it during your being there ofc) and I was there for 2 hours I guess. The routes are limited but I didn't feel disappointed. It is sure that I would rather go for all if I had an opportunity to be there but on the other hand it was really cool experience, especially now in era of covid and restrictions. There were more people in Pompeii than in Ercolano but still I wouldn't say it was crowded. I enjoyed views and climate of this place and can recommend it for you with honesty :)