Tom - Hear, hear! I've often thought that total tree removal frequently falls into the "baby with the bathwater" category. In addition to the examples you've mentioned other holes that, IMO, benefit from the strategically placed tree(s) are: Merion #4, trees along the right side really defines your tee shot, Merion #15, this hole is much better, IMO, with the right side trees, Aronimink #7, you want to play more right than center, but good luck on your approach if you do, Aronimink #18, even if your line of play isn't dictated on your approach shot, the right side tree is certainly a visual you need to contend with.
Nearly every year I get the opportunity to play golf in or around London. I can't help but think that the original "Heathland" designers were the first to really wrestle with the tree issue.
Lastly, and this is directed at that amazing course called Oakmont ... forget strategy, plant some more blasted trees so next time I view a tournament at your course I can at least find some decent shade!