As usual, love the log.
That flow drill you describe is great - I like when we warm up for class with it rather than mindless calisthenics, as pushups and squats do not mimic the moves you do when rolling.
I picked up a little tip a few months ago re: guard passing when training in California - when posturing up in someone's guard, tilt your hip cradle slightly forward so that the small of your back is flat (NOT arching the small of your back or rounding your back - just creating that neutral position). This creates the most stable structure, and allows you to resist your opponent pulling you back into them with minimal effort. I was rolling with someone in CA a few months ago, and every time I tried to posture up to pass, he grabbed my lapels and down I went. He showed me this little trick with my hips, and then I could let him hang off my gi lapels all day without being pulled off base
The counter to this, from the bottom, is to then change your angle of attack. If my opponent is postured up and I cannot break his structure by pulling him straight down, I shift my hips to the side and pull him from that angle. He cannot have good "base" in more than one direction at a time, so I just find the angle from which he is least stable.
Just my 0.02.
Thanks again for the log, Matt!