Ah, I see! Thanks, this makes it clear and also renders my question 1 irrelevant, indeed.
In my opinion it would make sense to add the clarification to the manual, e.g. to
http://manual.zorro-trader.com/ddscale.htm
http://manual.zorro-trader.com/zsystems.htm
The pages currently state "run a backtest with the Capital slider at the same position as in live trading at session start" and "Before starting live, run a backtest with the Capital slider at the same position as in the trading session".
So, if the reader knows that "stop and resume" means a new "trading session", then it is clear implicitly. But explicitly explaining the need of a new backtest with the current slider position after stop and resume would make that more unambiguous.

Yes, I'll make that more clear in the manual.

Just to confirm then, I'm trading live on a VPS that cannot really run backtests. So the procedure then is to run a backtest on my desktop PC whenever I want to change the slider, copy the resulting DBL file up to the VPS and then adjust the slider on the VPS?

I would say yes.