Temps - Don't worry about temps. Throw the temp gun away and tune for performance and smoke. To many things effect the temp any given engine will run at. Some guys run at 100 C, some at 115, some at 125. Depends on oil quantity and quality in the fuel, clutch set up etc. Anywhere between 95 C to 125 C is ok

Needles - will depend on what LSN you have in the carb (what generation your motor is).
Fairly safe starting point for most of the GO's is LSN 1.5 turns in from flush and HSN .5 turns in from flush. If you have a long LSN you won't need to go in any more on the HSN, just lean the LSN until you have a good tune (around 2.5 in from flush normally.
If you have the newer intermediate length LSN, then you will be able to go in further on the HSN (about 1.5) to get a good tune. LSN should be about the same.

Idle time - Hmmm no hard and fast rules there either. Again it depends on oil percentage in your fuel etc. I use a low % but high quality oil fuel, and can let my GO idle for a couple of minutes no problem - then gun it and it won't bog much at all. A higher percentage oil fuel will bog the motor down sooner and take off wont be as crisp after its sat for a while.
I wouldn't worry about it too much. Tune for a good clean top end, then tune the bottom so when you pinch the fuel line off (about an inch back from the fuel nipple) you get only a slight increase in revs (about 500 rpm) and the motor dies between 4 and 5 secs after you pinch off the line. This should be pretty close. It will idle as long as it wants to with the fuel etc you are using.

Hope this helps. Please no abusive replies - I'm feeling a little delicate after the last time I gave some advice on here