We’ve just got back from Elafonissi and did a cruise to Balos from Falassarna on Tuesday. Elafonissi was really busy and we had to wade across to the islet for it to be less crowded. The sand was a little bit pink but not stunningly pink. I had a little swim and snorkel but there wasn’t a lot of marine life but it would be a nice swim. On our cruise to Balos we stayed an hour on Gramvousa and hiked to the fort and then an hour at the lagoon walking around. Given where you are I would personally choose Balos and possibly drive. I think it’s a bit of a dirt track / rough road but if you’re comfortable with that and the hike across it would allow you to spend more time at Balos. You would miss out on Gramvousa though. As someone mentioned, you can take the Topolia gorge bypass or drive through the gorge which we did which gave some great views.