Choosing a base in southern Tenerife

We have ten days in Tenerife coming up and will be staying in the south, but we cannot decide whether to hire a car for the whole stay or only for the days we leave the coast. Our plans include a few beach days, so a car parked outside all week might be unnecessary. On the other hand, we would like to reach a few smaller places without spending most of those days coordinating connections. I started with all inclusive car hire tenerife south airport and realised I need to understand what is actually included before comparing prices. From your experience hiring a car there, which charges or conditions should I check carefully at pickup, especially around insurance, deposits, and fuel? We want enough downtime between longer outings. A split rental might work if collecting and returning the car during the holiday is straightforward. I would also like to know whether parking near the southern resort areas becomes difficult in the evenings. Would you hire only for the excursions given this kind of itinerary? It would help to hear what worked in practice.