Personally, I don't count the Clicker grab a cheap death at all. These are supposed to be VERY dangerous enemies, and it would have killed the immersion for me if I could get out of a mess I started by punching one in the fungus. Silence and stealth are key to dealing with those things, and when you screw those things up and don't get your gun trained on one in time, it should be game over. I understand why they have the companions able to hold clickers off - it would royally suck if you had to babysit them the whole time for fear of game over because you were busy dealing with your own stuff (classic "escort mission" PITA for some FPS). That is making it a more enjoyable game, imo.
As for the bow aiming, I wouldn't call it clunky since you can see the whole friggin arc where the arrow will fly. It's not EASY to hit a moving target with it, but it isn't easy in real life either. By the end of the game though I became much more proficient with it. Using it was about picking your spots and waiting for the target to move into your aim, not trying to follow the moving target.
The AI isn't perfect in this game, and I did encounter a few instances of weird enemy behavior/glitches, but I refuse to let that bring down my opinion of one of the best games I have played.