Hi Glqose,
I can answer your questions for you.
A1. The EAs place TP and SL on the chart. So when you disable the EAs the current open positions on the chart will continue to remain active until either the TP or SL is hit.
A2. Yes, with 10 portfolios running with each one containing 10 strategies MetaTrader will count this as 100 EAs.
A3. Not sure if I understand this question however I will give it a try. I assume you have closed trades equaling a profit of 300 euros and you currently have open trades equaling a loss of 400 euros. If this is the case you can either manually close these trades and take the loss or continue to let them trade. If you do not want any new trades to be triggered you can press the Auto Trading button in the MT4 tool bar to disable trading.
A4. The limiting factor with your VPS is the amount of ram. With 3GB of ram you should only run 3 MT4/MT5 terminals. One MT terminal for 1GB of ram. My VPS has 4GB of ram and my VPS provider suggests a maximum of 4 MT terminals. I looked at your VPS provider and they suggest 3 MT terminals for the plan you have selected that has 3GB of ram.
A5. EA Studio runs on a webbrowser. Webbrowers uses a lot of ram. So the reason why EA Studio runs slow on the VPS is because your VPS only has 3GB of ram. Your MAC I am sure has much more ram. This is the reason why EA Studio runs faster on your MAC.
Hope I have answered all your questions.
Kind regards,
Alan