The solar cover is the most important purchase. It ensures that the pool is heated but cools down less. It also keeps most of the dirt out.

The item has no heating and no pump. However, connections for the pump are available. Theoretically, a pool heater can be connected. I cannot answer how useful that is. But it could extend the bathing season. However, it would hardly make the pool winterproof.
Covering it with a solar tarpaulin in the summer helps quite a bit, I've had good experiences with that.

The item cannot keep the water warm and it has no pump, so it is not possible.