I agree with you regards the rough and playing corridors. Yes, the rough is challenging, but I had no problem making contact and advancing the ball near the green. Also, for the most part the only trees left in play are big, stately oaks that been limbed quite high so you can play underneath them. As few personal examples, I hit a drive very short and very right on the second. I had 230 left and was able to hit a low fading 3-wood under the trees just left of the front of the green. On 6 I was again way right, but was able to hit an 8-iron over the trees to get back in play on the par five. On 10, I was again way right (noticing a trend are we) and was able to hit a hybrid up near the green. On 17 I was (finally) left and was able to hit a low hooking six iron around a tree onto the green. On the last I hit a 7 iron from 180 onto the green. Granted, my rusty skill level is higher than the average golfer at the club but I feel the rough and trees are just about right.
There was a significant gap between long holes as the course plays for member play. However, the fifth, without changing tee placement, plays as a long par 4 from the back tees in local qualifiers. Also, the 10th actually plays longer than 17 and 18 because most good players are laying up to 175-200 yards because of the slope in the fairway. I am almost always hitting a longer second shot into 10 than either 17 or 18. The club could easily go to a brutish par 70 or par 69 by turning the fifth and 13th into par 4s but that's just scorecard stuff.
I agree that the third, fourth, and fifth are key to the routing. Getting around through that ravine and around and over the giant knob that the 4th green sits on is masterful. I also love the routing of the 12th - the long par 3 over the two ravines. It has some fairway between the two ravines and when I was a kid I would lay up in that fairway with a 6 or 7 iron and then a 9 iron or wedge onto the green.
Also, I agree that short par 4 14th still needs some work. Because it is impossible to run the ball onto the green there is zero temptation for me to drive that green - and it is only 280 yards from the back tee to the center of the green. Every time I play that hole it is 6 iron sand wedge without a question. The green is also unwise to go for because a miss right or left is likely a lost ball. But, it would be more enticing if the green front was opened up and central bunker was placed in the fairway in the ideal lay up position - say something in the right center of the fairway about a 100 yards from the green.