1. channels normally have fixed amounts. the default in Alby Hub is to get a channel with 1m receiving capacity from a LSP. This is typically enough for most users to always be able to send and receive.
2. yeah, sure. the wallet is there to send and receive. Zap hard here on nostr for example 😉
3. not sure if I understand the question. "channels" are there to send/receive. so you need one and all payments go through that.
