First question: When I first started this fascination with Bamboo 8 years ago, I began by digging three trenches and lining them with a 40 MIL barrier. One of the trenches has Bisetti Bamboo, and it broke loose at the seems, and has also jumped the barrier at one point. Bisetti seems to be a very vigorous grower up here in 7b. I have a feeling that this was the last trench that I lined that year, and was probably running out of the double faced tape supplied with the barrier. I have the situation under control now, but need to know how to fix the barrier. I wanted to know if I should dig up around the two seems where the breaches occurred and re-tape it with a better tape, and in more places, or maybe go through the extra effort and get a clamp style seem like the one that is sold by Tradewinds. I was also wondering what happens to the rhizome after it is pruned? Does it continue to grow, or does it stop right there? If it stops, maybe it will block other rhizomes from growing past the seem and I can just dig a little and check the seems for new growth twice a year? What would you do?
Second question: I have some PHY Aureocaulis growing in a round retaining wall that is 20 feet in diameter, and 21 inches high at it's lowest point. It is constructed with EP Henry Blocks and it is located on a very firmly packed stone driveway. The stones at the base are 3/4 inch limestone with a 6 inch packed base. The Aureocaulis, much to my delight, is doing very well now on its fourth year. It hasn't even come close to filling the circle yet, so I figure that if I need to make modifications to the wall like making it higher, and adding a barrier to the inside edges, now is the time to do it. I want to be extra careful with this one, since my neighbors well manicured yard is only 30 feet away, and I don't want any accidents to happen. Any advise? Is growing Bamboo in a retaining wall a bad idea? I don't want to do any more work that I have to, as the EP Henry blocks are very expensive, and so is the barrier if I need it. Remember I am in zone 7b, so I am not sure if the Aureocaulis is going to take off like the Bisetti did.
Third Question: Is there an average distance a rhizome will grow before shooting? Luckily the Bisetti in question one put a new shoot up only three feet or so from where it jumped the barrier. If not for that, I may not have discovered the escapees until it was too late and crossed the property line. The answer to this will help me in future plantings, so I know that it is not the end of the world if I miss a rhizome while pruning.
Last question: For those containing runners by rhizome pruning, does the Boo eventually become trained? Does the Bamboo eventually give up growing in that direction making pruning easier, or does it get more aggressive?

Again, thanks to every one here for all of the valuable information. I wish I knew about this forum when I started eight years ago.