[Nevadaref]

Despite the above post, the correct answers are:
1. Yes, in NFHS play a player or coach who has already received enough fouls or technical fouls to merit disqualification can and should be charged with additional technical fouls for poor behavior. However, the NCAA has the following provision which prohibits this: (Rule 10, Section 2, Article 2) "When a player, member of bench personnel or coach has been ejected for having incurred the maximum number of technical fouls, no additional technical fouls shall be assessed."

2. Yep, sure is. Rule 10, Section 1, Articles 1 through 11 are all TEAM technical fouls which are not charged to a specific individual, but only to the team as a whole and count as part of the 10 team fouls per half towards the putting the opponent in the bonus.

3. Not directly. In NFHS play, the head coach receives an indirect technical foul for each direct technical foul charged to someone who is bench personnel. On the third indirect the coach is DQ'd. The head coach cannot by rule be assessed a direct technical foul for something that someone else did. Direct T's are only for that specific individual's actions. Two direct techs equals disqualification.
The NCAA has a ruling that the head coach can be charged a direct technical foul when the offender on the bench cannot be identified:
Rule 10, Section 9, Article 1
"A.R. 10. The official is advancing up the playing court to cover the play and as the official passes Team A’s bench with his or her back to it, someone on that bench uses uncomplimentary language. The official is certain from which bench the uncomplimentary language came but not from which party. RULING: When the official cannot, with assurance, determine the violator, the official shall charge the direct technical foul to the head coach. The official alone shall decide to whom a direct technical foul shall be charged. It is not the prerogative of the coach or other bench personnel to come forward as the party guilty of unsportsmanlike bench decorum."
But again the NFHS does NOT have this rule.