1)
While I don't have a mac, according to
this, the address is correct. You should have an armyops folder in there where the AA files are.
2)
I'm unaware as to how this would work. As far as I know, most of the time people run the scripts from their own computer.
3)
Yes, all of it does happen through the player ID usually.
I'm pretty sure ELiZ made this work already. Try "afc random". I'm fairly certain I saw the code for this somewhere, but can't find it explicitly so I'm not sure if it works, ELiZ can comment I suppose.
If it doesn't this is a good suggestion:
If you place an executable in the System folder, it's the job of the assist client to make it disappear.
Making an app that would create random.txt regularly without being itself in the System folder is childplay. and average coder could do that in 5 minutes.
You can make an extremely easy piece of code that makes a new random.txt every now and then (a minute or two to make sure you get a new set every round) where everyone gets a random weapon. The only problem with this would be that it would still rely on the IDs and spam all the IDs which makes the server and/or client freeze for a second or so.