1-Not personally paying, but do use them:

Client 1: Copilot - They provide up to $1500 in credits but I barely scratch $300 per month.

Client 2: Claude Code - unlimited usage, however I barely scratch $400 too per month.

2-Not using outside models or weird stuff

3-Answered above, default CLIs

4-Never got the time or seen how it's done. I think it's not that useful at least for me

5-Not using any of those, but grok bot looks promising