Depends who you're going to be selling to. In the indie market, using mousewheels and third buttons is a big no-no, nay, frowned upon. Even using TWO mouse buttons is dodgy territory.
For map editors and game dev tools (sorry I have no idea what FlowED even is), I don't think that using 3 mouse buttons and a scroll wheel would be a huge concern.
For map editors and game dev tools (sorry I have no idea what FlowED even is), I don't think that using 3 mouse buttons and a scroll wheel would be a huge concern.