If I update my MacBook Pro (running Mt. Lion) to Yosemite, can I still use the iDVD that I have on the machine? And, are there any programs that I can expect to not run anymore after the update? Also, I just updated my iPad Air to 8.1.3 and now I can use iMessage with non-Apple people for texting, like I do on my iPhone 6. I am not able to do that on my MacBook Pro. Does that become possible after I update to Yosemite? I have been putting it off, not sure of the benefits and worried about new glitches. Thanks.