Hi
If you want your friend to listen and make notes on your work I would think an MP3 bouce file of each song would be enough. You could bounce down to WAV if you want a higher bitrate and better sound for mastering but I doubt he will critique your sound quality on an MP3 if he isn't gonna make any changes or matering work on the project. And WAV files of each song would be a lot bigger size wise too so I would do MP3 bounces of each song.
Make sure all the levels and Master track is good and not peaking in the hard yellow when you bounce. In PT11 it takes a second per song so do a few tests and make sure everything is A-OK before you commit.
When you bounce just mark the whole song from start to finish and start the ounce. If you don't mark the exact song the bounce will continue as long as your harddrive can take it
so be very careful and exact in marking the start of each song and ghe end of each song. You can leave a bar or a half of a bar in the end but the bouce should be exacly from start point of the song.
Goto bouce to disc and make sure the settings for "interleaved" is checked so when you bounce a stereo file it comes out as one file and not two (L and R) files. Good luck with the project and if you have invested 2 yrs I hope it pays off somehow for you
PS. The older file extensions you mentioned in "bounces" you probably were thinking AIFF files but they won't play on most portable or stationary players like iphones ipads and equipment that plays normal MP3 and WAV tracks.
Best of Luck
Christopher