As all of those questions are about the solo, they should really go in
the solo thread.
A mod will probably move this at some point, but until then, I can give you some answers
1 - I pack a stem, put it in the solo, and then turn it on. once its up to temp, its ready to hit.
If I'm putting a stem into an already hot solo, I either wait a minute, or just start puffing - your draws should heat the stem up a bit quicker than letting it preheat on its own.
2 - I don't wait. Hit, Hold, Exhale, repeat
if you notice the vapor getting thinner, maybe give it 10-15 seconds, but I haven't noticed any need to wait between hits.
3 - I usually just wait until the vapor gets particularly thin, then its done.
It usually takes me 8-12 minutes to finish a full stem (but will vary depending on your hit style/preferences)
Oh, BTW
Welcome to FC