In order by paragraph:
1) Yes, Cost Savings.
2) I have "Export=Everything" and "Grid Charging=No". "Export=Everything" and "Grid Charging=Yes" is prohibited by the CPUC and PG&E, although I don't know if the app enforces that.
3) Yes, an EV.
4) In this graph mode (which took me a little while to grok), if you ignore the colors, it is showing just net import/export from the grid. The colors are trying show where that grid energy came from (export) or went to (import), with some important caveats:
Before I start exporting solar, it's not showing you the PV production which is charging the PW. When I'm exporting solar only (before Peak), it's not showing you the house load which is reducing the PV export. And when I'm exporting from both PW and PV during Peak, it's not showing you the house load, which is also powered by PV + PW.
So I prefer the earlier view that has all 4 quantities on one graph, not sure if that's still available since the app update, I haven't been reading that thread.
5) Good question, I'm not sure myself. Speculative answers, I don't have enough data yet to tell: (a) 2.7 kW is related to my PV array size (although in the PW wizard that is set to 2.4 kW DC, I think). (b) It's a fixed limit (possibly per Powerwall) for grid export behavior, (c) it forecast my Peak PV production, my house load, and knew my PW charge level, and computed that 2.7 kW was the required discharge rate to end up at the Reserve level at the end of Peak.
6) I did end up at the Reserve level, not sure if that small blip just after Peak is some final correction. If so, I think it was a mistake (undesired behavior of the algorithm).
7) As per (2) I can only export PV generation. But PG&E does know your PV size, and does look at your total annual exports, and disallows NEM credits for export in excess of what its theoretical model of your PV says you could possibly export. To enforce the "no pure ESS TOU arbitrage" rule.
Cheers, Wayne