I try no to optimize too much, this is a p2p network so it's shifting and evolving every day, not easy to map the reality, this month one channel could be bad and the next a good one, it's all depend in the time-frame you want to analyze it.

If you manage the fee/htlc you are safe, just let other people open channel if they want and only close in the extreme case, for example 4 months without use and the peer is connect only to 2 more nodes.

If it's a private channel... never close, maybe you are a LSP for a pleb that need it.