The examples and connection to real life experiences are outstanding. I think the pool example is something all students have experienced at some point. If not a pool, then a shower after waking in the morning or right after a workout is very similar. I think your hook will grab the students attention and really engage them in the topic.
I like the idea of using the clickers to assess student understanding. You stated that there wasn't much socialization in this lesson. What if you assigned the class clicker problems, and then after getting their individual results, place them in groups to discuss their individual answer and try the practice problem as a group. I would place them in heterogenous groups to make sute the student having trouble work with students who apprear to be understanding the material. Then after the group work, give another individual problem, similar to the group problem, and re-assess.
There are no techical problems. The document is very clear, well organized, and easy to read.