I've been doing the same on a demo account Sharks. I've had troubles with EA's interacting with each other when they shouldn't. Im getting ahead of all of it now, although It has been pretty frustrating.
I had an idea recently to program an overall account display, sort of like an EA that I could attatch to a blank chart. Where it would monitor and oversee all EA's on each individual symbol, and display where it might be breaching drawdown limits. Present weekly/monthly/YTD profits. Im sure theres some of these on the mql5 forums somewhere but I think it might be good for practice.
How many models have you got live now? How are they performing?
