Priorities in BJJ

I chatted with Niko Han last week, and he reminded me one of the main principles of BJJ:

Priority#1 is to defend submissions.
Priority#2 is to escape bad positions.
Priority#3 is to maintain positions.
Priority#4 is to improve position in order to get a submission. You can go for priority#4, as long as priority#1-3 are always in-check

Why are these so important? Let me elaborate more:
1.) Attempting to escape bad position without defending submission will lead you to a submission. In fact, such reactions are used by BJJ practicioners as a setup for a submission.
2.) Further down you are on the hierarchy of positions (See: http://bjjvoice.blogspot.com/2009/01/hierarchy-of-positions.html), the more you have to defend as your opponent have more options to attack, so you'll need to escape bad position in order to minimise their offensive options.
3.) If you can't maintain position, you'll get swept back to bad positions, thus unable to attempt any offensive to your opponent.
4.) Again - the higher you are on the hierarchy of positions, the lesser options your opponent have for escape, and the more options you have to submit your opponent. Note that maintaining position has higher priority compared to submission, as submission attempts often provide room for escapes / reversals. Therefore, unless you're so sure that the submission is sunk deep, abort the submission and defend your position.