Tip: Use a transmission funnel (very very long funnel) for easier feeding. These can even be rigged to your nute bucket with a dowel rod and a little duct tape.

Root Sharing: The intermingled roots will share nutes, not fight for them. If your using different phenos and there is a dominate female, she will of course absorb more nutes, but that's just a dominate plant, the rest still have access to the nutes they can absorb. Not sure how much sense that makes, you can lead a horse to water, but you can't force him to drink.

Culling Males: Yup, plants die in nature all the time, the plants around them absorb their nutrients. That's why your eventually left with a bit of waste - Its not going to harm your other plants root system(s). Basically all the additional space your giving them, is going to make them much stronger than they would be in the solo cup, remember the soil is just a medium, you can grow in anything, and the plant is only limited by the regulations YOU give it - Even the fact that you can LST from the beginning even though your on 12/12 just because your giving your roots more grow space is worth any con (such as culling a male by cutting)