1. You can optionally leave the account parameters empty in any of the eSignal NinjaTrader functions and NinjaTrader will use the default account.  You can set the Default account by left mouse clicking on the File menu in the NinjaTrader Control Center and selecting the menu item Options, once in the Options window select the ATI tab and select the account you want to use from the Default account menu.

2. To ensure you do not place duplicate orders in the event that an eSignal chart reloads you can check for the condition "isLastBarOnChart()"

3. You can check NTMarketPosition for a flat position before placing an order

4. You can create an orderId using the current bar time stamp + instrument name. Before placing an order, call NTOrderStatus and see if you get a valid return value. If yes, then the signal has already been processed.