Yes, I would do away with the crunches.

Any exercise which puts the lower back into flexion (rounding) should be avoided as much as possible.

The side bends are the same. The only shape that the spine can handle, apart from its neutral position, is extension (Like a cobra pose). That's why I spend a lot of time laying on my stomach and working.

Sitting, however, almost always will force your back into flexion. So, most of the time, I stand or lay on my stomach and work.

Thank you, I am trying really hard to keep it simple;)
Oh, haha. I was laughing at myself, with those lunch boxes. I had to get creative :)

The new video is up by the way :) Please check the description and comment on a question I asked the community.

Thank you in advance ;)