When you restart your MT4 terminal the open trades will remain open. The only problem I see is if you have an open trade that is very near hitting its TP. So, if while restarting the terminal and the market moves to the price of your TP price level the open order will not be closed because the terminal is not able to send the TP signal to the brokers server. So, as long as none of your open trades are not close to a TP or SL price there is no problem with restarting your terminal.
During the weekend any open trades you have will remain open.
Alan,