You can use DX11 without issue.

64-bit Warcraft is a no go, for the current version.
But will likely be available as part of JoeMultiboxer (IS Boxer 2), when it releases.



If you want very accurate mouse broadcasting, enable instant swap.
That has every window rendered at full size, and then scaled down to whatever your display resolution is.
But you can disable instant swap, it is an option you can choose to use or not.
If it is disabled, IS Boxer won't use more resources than other boxing options.

Your choice pretty much, it's incredibly flexible.