I'm curious what other people would say about #4. The only two answers I've ever heard are to become a chief architect (that seems to be the only seniority path that isn't management), or just go into consulting.
There are a few flavours of seniority for ICs - deep domain expertise, deep skill set, high productivity, high flexibility, able to design and communicate and drive large-scale changes, mentorship, and non-technical organisational leadership like running a training programme, improving hiring, and so forth.