There's obviously a fine line betweeen muscles for strength maintenance and power, and just getting stiffer. How do I know when I bulked enough? Or should I just ignore lifting all together and focus on dumbbell shadow boxing? I'm interested in punching as hard as I can, since I have always been fascinated by power generation. I am not looking to spar.
there are sensors that can give you the results about punching power. Buy them, hit the beg and see what are the results. You can also compete against other people online, fun stuff. Never tried it, but if I'll ever have shitload of money, i would buy it.
You want to punch as hard as you can yet you don't even want to spar? Seems like a waste of time. Why do you want to learn something to that extent and not use it? Bulked enough? How much you bulk up is up to you. Don't do dumbbell shadow boxing, it's just bad. If you just want to punch hard, practice technique. A lot.
I think the thing with bulking up is it'll most likely push you out of your natural weight class thus making you less powerful- I don't think a human can naturally put on so much muscle as to actually inhibit good form.
You don't have to bulk up to generate more power, you have to get stronger and more explosive. If you just bulk up, you may actually end up generating less power if you bulk up muscles that don't relate to punching. To maximize strength for punching power, focus on plyometric exercises and anti-rotational exercises. That'll develop your serratus and obliques where a lot of punch torque is developed. If you're going to lift, focus on compound lifts that require the whole body working together. Deadlifts, front squats, bench press. High weight, low reps. You won't necessarily bulk up, but you'll get a lot stronger. Avoid isolation exercises. Things like bicep curls are useless when it comes to power development and in fact the added bulk will slow your punches down.