Answer:   Ninth

Details:   Playing from a NPZ (ACC) is prohibited and free relief must be taken [Definition: No Play Zone and Rules: 2.4 and 16.1f]
Each stroke from the NPZ counts and a 2-stroke penalty applies [Clarification: 14.7b/1].
Liz's next stroke will be her ninth.

Answer:    True

Details:    No penalty applies as this is stroke play.
David and Greg may share a caddie [Rule: 10.3a(2)].
David and Greg are outside influences with respect to Wayne's ball and therefore no penalty for lifting Wayne's ball [Rule: 9.6].
The ball must be replaced by either the player (Wayne) or the person who lifted it (shared caddie) [Rule: 14.2b(1)].
However, as this is four-ball, Steve may act on behalf of Wayne and therefore is also authorised to replace the ball [Rule: 23.5a].
Note 1:  If David, Greg or someone else replaces the ball and Wayne's plays it, then Wayne gets a 1-stroke penalty [Rule: 14.2b(1)].
Note 2:  If Wayne plays the ball that was replaced incorrectly and this knowledge comes to his attention after a stroke has been made, then no penalty applies [Clarification: 9.6/3].

Answer:   Just a 2-stroke penalty applied to fifth hole

Details:   The club (8-iron) was added during the play of the fifth hole.
David only became aware of the 14-club limit breach before starting the sixth hole.
The added club (8-iron) has been correctly taken out of play, therefore he is not disqualified [Rule: 4.1c(1)].
The penalty is applied to the fifth hole only [Rule: 4.1b(1) ... see penalty statement at end].
Note 1:  David is required to remove the added club, as this was added during the round.
Note 2:  If the added club is not removed, David would be disqualified.

Answer:   None

Details:   When Greg incorrectly substituted a ball, that ball is in play [Rule: 6.3b(2)]. A penalty only applies if a stroke is made at that ball [Rule: 6.3b(3)].
When natural forces move the ball in play (general area to general area), that ball is to be played as it lies [Rule: 9.3].
Greg is entitled to correct the incorrect substitution, but must be undertaken at the current location [Rules: 14.5a and 14.5c].
Note:  In correcting the substitution, the ball must be marked before being lifted [Rule: 14.5c].

Answer:   Seven

Details:  Liz is permitted to initially play a provisional ball [Rule: 18.3a].
The crux ... Liz's original ball is 'known' to be in the penalty area.
Liz may take any of the penalty area relief options for just a 1-stroke penalty [Rule: 18.3c(3)].
After making a stroke at that ball, Liz's had 2 talent strokes (TS) and just 1 penalty stroke (PS).
Four more strokes gives a total of 7 for the hole.
Note:  If Liz decides to play a ball as it lies (in the penalty area), she may choose either ball and her next stroke would be her fourth [Rule: 18.3c(2)].

Answer:    Liz [6] and Jill [DQ]

Details:    When Liz tapped tapped Jill's ball back to her, Liz gets a 2-stroke penalty (scores 6 for the hole) and Jill must replace the ball on the lip of the hole [Rule: 13.3b].
Also note, the 10 second wait time no longer applies (ball has been lifted and replaced).
When the ball falls into the hole, Jill is required to (again) replace it on the lip of the hole (ball has been lifted and replaced before) and complete the hole [Rule: 9.3 Exception 1].
As Jill has not completed the hole before starting the next, she is disqualified from the round [Rule: 3.3c].