Personally I think the coolant should flow through the matrix constantly, control the heat via flaps in the heater box,
when there is a valve shut off all summer come the winter, open the valve (if it's not seized), more often than not
will leak or, the matrix could be blocked due to no flow for...
Don't about the specific tool you mention but, I've found with special tools in general not to go for the cheapest,
middle of the range is better unless, you are using it regularly then only top of the range will do.
If you're sure which way it's rotating, it can't hurt you but, I wouldn't risk it either, a newspaper could also be
dangerous if you poke it the wrong way.
Some of the reg's go for stupid money, my two initials followed by the number 1, was once for sale for £60k,
four numbers followed by my initials could be had for a couple of hundred but, I can't be arsed.
Looks like a PO has been a bit careless with sealant, similar done on a sump gasket can destroy an engine
when, the excess sealant blocks the oil pick up strainer.
What I would say is, if you must watch something on a screen tablet/etc, sit in the back so as not to distract the driver,
I would have thought it would be illegal if, it was visible to the driver anyway.
When I had my 4.6, I didn't use it at lower speeds but at 80 it held steady, rarely used it though, wasn't very often I had traffic
conditions to maintain a reasonable cruising speed.