Those distances in money depend on many factors (lot size, leverage...). You should use pips or points instead in order to make it more replicable to any chart.
Hello,
Since the pairs trading backtest isn't working properly for you, I assume you are using MT4. MT4 doesn't support this.
You should use MT5 for pairs trading. Generally speaking, you can enter the symbol EURUSD for the "Buy" block and the symbol GBPUSD for the "Short" block.
Yes or not... but depending on what you mean yes it is possible, the indicator tab in your project page allows you to add indicators and then use it while creating the EA.
You can create a free scalping EA here, but it will not be complete... just working. mql5 website has many but if good will cost to purchase. Your best bet is to decide on a strategy, create, test, test... then you may get a working EA.