Need a little help tweaking a HAL file

I have really minimal expeirience tweaking HAL files, I hope someone can help.

I have an Arduino board communicating with HAL via the USB port.

Details if interested can be found here: forum.linuxcnc.org/10-advanced-configura...oard?start=10#304669
When I stimulate an Arduino input the target in HAL watch changes, when I change the status of an output from within HAL watch using the set and clear buttons, the output on the Arduino  changes as commanded by HAL.

I'm now thinking about the data I need to transfer and how I would go about that using HAL. If I can do the following I can probably figure out everything else I need to do.

Questions:
1) At the moment I need to execute "loadusr arduino-connector" in HALshow to start the python program that receives the serial data and then passes it to HAL, How would I do this automatically every time LinuxCNC starts?

2) I would like to run a single bit loop timing test, and see how fast or slow a round-trip message takes. So assume I will activate Arduino input 7 and then I want HAL to activate Arduino output 8 when and while input 7 is active. I will then scope the response.

3) How would I activate output 9 when
a) machine power is on
b) when say the MDI screen is selected

Much appreciated

Jeff