Greg's recommendations are good. However, I would recommend increasing your settling times to at least 5 seconds. Better over-long than under. Exposure times are completely dependant on equipment and seeing conditions. You have to find the point where the plate solves are not having any problem (except occasional points) and you are good. If you get a point that doesn't solve, then rerun those points only after your first run is complete.
I completely agree with running the cable off the back of the OTA and not down the counterweight shaft. A flexible cable (or cables) will work very well off the back. You just need to make sure they are long enough to reach all positions. I have never had a snag this way. The problem that I see with running them down the counterweight shaft is that are coming off a point on the mount furthest away from the axes of rotation and as a result they will always place some pressure on that point, even if it is not much cable. A cable running off the back end of the dovetail is far closer to the axes so it results in far less pressure.
The tripod extension does make some sense. In a cheap tripod, this position would be terrible due to all of the flexure that occurs. In a tripod like the Aries (or Centaurus), the extension does not result in the same amount of flexure while it does increase the circle of the legs which provides greater stability overall, particularly with a "lighter" system. It's another one of those differences that you might not think about if you come from a mount and tripod that are not of this quality.
Getting rings for the Takahashi is a real pain. Only a few scopes have TAK rings available. Finding aftermarket rings that fit the TAK scopes (or just about any scope for that matter) is difficult. I looked around for some rings for my new 60Q and could find only those from PrimaLuceLab and a company on AliExpress. I got the PrimaLuceLab rings but at the weight of this system I'm not particularly concerned. Someone needs to produce a material that is flexible, won't compress, can be easily cut, can be glued to something, and won't mark up the scope to solve the felt problem. I don't like the clamshells since, because they are designed to mount directly onto a TAK mount, they are not really designed for dovetail mounting. There are some good aftermarket remedies for that, but it is still a use they were not designed for. Also, attaching an upper dovetail is far more difficult to do with stability on the top of the clamshell.