No it does not! I have swapped hard drives and even installed a second SSD and found no issues or proprietary issues! Update: You should also watch your language and there is no real issue with the iMac sensor for anybody with a little skill!
OWC "Macsales.com" has 16gb 2x8 for the New 13” MacBook. Apple officially has stated Maximum at 8gb but is fully capable of supporting 16gb.
I too have successfully bought the iFixit 2nd hard drive kit and installed an OWC Mercury Extreme SSD and loaded the OS only on it which has really made a huge difference and increased overall speed of my 2011 Mac Mini. I found it fairly easy to do and have also upgraded Ram to 16gb. I am extremely happy with the results. I encourage anybody to try the SSD option to load just the OS option on the SSD. I most cases you can get away with a very affordable 64gb SSD drive.