No, it shouldnt by default. It optimizes profit. Only If profit is higher when discharging first, it will discharge.
It also takes the energy losses into account, not just the price difference you set. Actually it is not using the setting as a price difference, but as a cost factor to charge+discharge 1kWh. You should set it a bit lower then what you were used to before. What value did you set?
It should already do that. Again: profit is what is optimized. It will take the actual SoC and minute of the current hour as starting point.
As a basis yes. But it can combine these within an hour (e.g. 40 minutes high load, 20 minutes low load). The proposed power will then be a weighted average.
