1)
Try checking the timing it seems like after awhile the timing might be off
2)
I think this is a common problem cause my 2vzfe takes like 5 min of idling before the temp gauge begins to move a little. This may be attributed to old thermostat? I've had no problems with my car even with the delay.
3)
Not too sure but this may be an electrical switch issue.
4)
This I'm pretty sure is attributed to your cold start valve I bought mine off of this guy on
ebay. It should be a simple switch.
Good luck hope this helps!