MacOS – MacBook Pro Retina running Bootcamp with 2 external 27″ monitors

Since it's an intel chipset on the logic boards and Apple is on the hook officially to provide driver support for Windows 7 - the only possible drawback might be the keyboard layout and Thunderbolt. It's quite new, so I don't have any real great feeling for how well that works under Windows 7.

Even in Mac OS X - thunderbolt doesn't have any direct networking support - just video, storage and target mode at present. Intel and Apple are working together on Thunderbolt and the active cables mean that even if PC decide to implement an optical interface rather than copper - you might not be left out if you need a PC Thunderbolt accessory 6 or 9 months down the road. My crystal ball works so poorly for Apple - I'd hate to try to guess what PC vendors are going to do even if they aren't as notoriously secretive as Apple.

I would have no hesitation to run Windows 7 in emulation - the virtualization is so robust now - you can choose to have unfiltered net access, share an IP, virtualize a router. You can always fall back to BootCamp if needed, but I wouldn't worry about that unless you have specific credible advice from someone that knows your exact workload and style of how much control you need. With minimal learning, you should have VMware or Parallels doing exactly what you desire.

It is impossible to deliver an "answer" to this question. You are asking for something that is purely opinion-based. I have friends who use super small fonts and it's very comfortable for them. I also have friends who use larger fonts, and that works best for them. I personally use a variety of font sizes depending on what Mac I am on and what App I'm using. Your best best is to work with whatever font size suits you, despite what anybody else tells you.

There is no "one-size-fits-all" answer to your question.