Small bud at low height

Once removed, they should not grow back normally. Google "lollipopping cannabis" it is a great technique and I am a big fan of it.

You'll definitely see a correlation to bud quality relative to depth. This has additional variation per seed grown. Some plants develop far better nugs deeper into canopy. As long as you don't remove too much, it won't hurt yield and you will have a greater proportion of 'better' buds vs larfy buds. The canopy and co2 will mostly dictate yield. the plant will be able use it's photosynthetic energy production as long as you don't remove too much. https://www.cocoforcannabis.com/community/photons_corner/to-defoliate-or-not-to-defoliate/ This guy puts things in perspective well and debunks more than a few myths along the way. It's something that is a judgment call and needs a little personal trial and error to get familiar. No one can tell you a step-for-step path because you need to handle big stretchrs differently than shorter plants... at the very least best timing to do it is impacted.