Where to place RefreshRates()?

Where to place properly place RefreshRates() to prevent re-quote/off quote?
Should it be before or after?
Are these right?
Where else should I place RefreshRates()?

It has no effect to rebuild quote buffers unless you expect a relevant delay in your method - e.g using a loop instead of using the OnTick event. But when you do have the delay involved, then use the RefreshRates in the beginning of your calculations, i.e. when the loop cycle starts.

I don't believe that RefreshRates() refreshes MarketInfo data.
As you don't use any of the pre-defined variables in your OrderSend(), I don't see that RefreshRates() is necessary there either. It would be if you were using the chart symbol and Ask and the EA had been calculating for a while.