I can help with some of that. Just install MT4 into a new folder, as long as the folder have different names it will be a separate instance. Open it from there, that way you can have several MT4's running on one machine.
I draw the line at 8 or so, but if you have bigger machine you can run more. MT4 does have memory leaks so be sure to keep tabs on how your machine is performing. If CPU usage gets to 100% it starts missing trades. To get around this I have automated reboots.
Also you can copy the files into the MT4 directories like the profiles for example, then you don't have to keep setting up each new version.