That's a lot of questions! And huge topics! This would be a book-length post if we tried to answer them all. Instead, we're going to direct you to a post we wrote for the EssaySnark blahg two years ago:
What about an online MBA? That should get you started in evaluating this as an option.
In the two years since that was published, more schools have announced online and hybrid programs, including the FEMBA Flex at UCLA and IE Global in Spain. There's the Tepper FlexMBA and Kelley Direct. Smith and GWU also have programs.
An online MBA is definitely a different experience and it needs to be considered carefully. You're missing out on a lot - but there's some benefits as well. It is a very individual decision and you'll need to weigh out the pros and cons. It's still an MBA in terms of the education but the experience is not the same, and opportunities may be different as well simply based on that fact.
It sounds like you're just getting started in your research. Hope this helps you move forward; if you have specific questions that we can try to address please let us know.
EssaySnark