1. Given the option, i would use E10 93. It's cheaper, has a very marginal impact on MPG, and i believe is better for performance - That's a discussion for another thread though.
1.5. Yes, if you're running 93 octane, of any sort, that would count as a 93 tune.
2. The wording is misleading. A lot of tuners will claim massive CURVE gains, meaning the most horsepower it picked up at any given point, not PEAK gains which would be an increase in max quoted numbers.
3. Here it gets tricky. Yes, the Ford system is ducted for cool air, and is actually a decent shape for airflow. I've done testing where the airbox will actually become a vacuum zone (meaning the engine is still having to work to pull air) at WOT, but in the real world the gains are negligible. I believe adding a CAI is good for aiding throttle response and a good platform for other mods, but in and of itself i would not expect greatness. Again, another discussion for another thread (please dont start a new thread, there are hundreds on the topic already).
4. Certain CAIs require tunes, certain do not. If the MAF diameter changes with the new intake, a tune is 100% required because MAF diameter is a critical component in fuel calculation. So yes, in some cases you will need to purchase a tuner for your CAI.
5. I'm not certain that other company's (SCT, Diablo, HP tuners, etc...) tune files can be written to the Ford Procal. If you're wanting a tune from an aftermarket company, AED, Lund, VMP, etc... you will need to contact them and see what their preferred tuning device is.
A lot of these topics are covered in depth on this forum, but i understand the search feature is a bit hard to use. Not all of the information will be Boss Specific either, so you will have to interpolate a bit.
For the best results, go to google, type your question and then follow it with mustangevolution
For example, Boss CAI:
https://www.google.com/search?q=Bos...ZAhVJRqwKHUN1AfQQrQIIQigEMAA&biw=1920&bih=974