Thank you very much for the feedback , it really cleared some doubts i had!!

Websites will always continue to evolve over time. Adding to content, adding images will not affect ranking negatively, it may even help the ranking. Now, if keywords in title change, or keywords in body change - different story. But, google likes to see website evolve and long as it always leads to more relevance of what the person is searching for.

Thanks for the great question
Blessings

I doubt it will effect the rank. Google loves post that is dynamic and updated from time to time. As long as you don't change the post url, it should be fine.

:)
Joe

I doubt it, but very good question. The reason I thought no so is because you are making it more relevant and more info, which shows more of sincerity in your website. I look forward to seeing the actual answer though. This was an excellent question!