1) If you have the JMerc bracket, you dont need (pretty sure you can't even use) the comptech one.
The way the JMerc bracket works is basically it re-positions the power steering bracket so you can use the OEM auto tensioner (in place of the JRSC manual tensioner or the Comptech tensioner which comes with the supercharger kits). So I'm not sure why the previous owner is giving you both. Maybe he had issues with the Comptech tensioner and got a JMerc bracket. Or vice versa.
heres a pic of mine installed.
2) I was going to try the Type Spaz way of the power steering, but its basically has to be perfect. There is a chance it can leak. But if you still want to try it, let me know. I bought that metal water hose thing because I was going to attempt it, but chickened out.
3) The datalogs take anywhere from 5 to 15 mins per "round" (depending on how much work your setup needs and how the roads are in your area). But remember, Magnesium isn't just sitting around all day waiting for you to reply. So there is a chance you do a datalog at 11am, but he gets back to you around 9pm and then you might not be available to do a datalog. There were some days where we got 3 datalogs done in 1 day, but sometimes just 1 a day. I'd say you will need at least 5 days
He'll give you specific directions to do the datalogs. Very easy to follow. Basically what he will tell you to do is drive 5mph for 30 secs, 10mph for 30secs, etc, etc. Then another driving in 1st gear at a certain RPM for 30secs, 2nd gear at a certain RPM for 30secs, etc, etc.
So yeah it can get a bit time consuming
4) Also, don't forget you need new spark plugs.