Hello Mr. Ashish,
Apologies for the late reply.
1. There will not be much difference between ID for an online course and ID for a Learner Centric MOOC. I am an Instructional Designer with over 15 years of experience in working on online courses. My experience with the LCM model is that it is more suitable, than any other ID model, to create a MOOC.
2. You typically don't need any authoring tool to create a MOOC based on the LCM model. However, there are other video editing tools that would be required.
Regards,
Ganesh Lokhande
Discussion Forum Coordinator