Hi Godoftrading,
Sounds like you have a pretty good idea of what you need! I don't really have much experience with NinjaTrader, but as far as MT4 is concerned, here's how I can envision your needs working out:
- Hotkey Trading: You can accomplish this via the "Scripts" feature of MT4, and assigning a hotkey to it. Here's an interesting script you can use for reference (unfortunately the interface is in Russian): http://codebase.mql4.com/3582 and also this one: http://codebase.mql4.com/3351
- Bracket Orders: This is something that will likely have to be done as part of the script above, as it will take quite a few clicks to do this the 'normal' way.
- % Take Profit: Also part of the script, as it is much easier to do math calculations as part of an MQL script, than trying to get MT4 to do it your way otherwise. This should be relatively easy to do.
So the more I think about this, the more I feel you'd need to use the Scripts functionality of Mt4 to develop your system according to your specifications. The great thing about scripts is you can assign a hotkey to them, while their behavior is entirely customizable.
I wish I could do more to help you in NinjaTrader, but its just not something I am familiar with.
PS: I am going to move your post to the MT4 forum, where you might get more help.