Need help understanding syncing accounts

Hi,
Ok, so I have finished my shiny new strategy and want to try it out live. I've read the help file on syncing account positions and can't make heads or tails from it. Presumably, I come in in the morning and have no open positions (at least I better not!). Assuming this, the 2 "Wait until flat options" don't seem to apply.
I don't understand the other 2. Do I want Sync account position set to true or false? Any guidance would be greatly appreciated.
Thanks ... Ed