1) Yea, you don't
need PE licensure.
2) Maybe in the US, I agree not much is stamped. However in places like Canada, stamping is pretty much mandatory in most areas (even Ontario, which has an exemption, is seeking to require stamps on most drawings and technical documents). I work in the mining and minerals processing industry and, during my time in Canada, almost everything I ever produced that was going to be built or purchased had to be stamped.
3)
Certified engineers aren't going to get paid more if a cert is not required
This is untrue. Loads of companies are looking to hire PE's as it adds a level of professionalism and status to the organization. If company X's prices are similar to company Y's, but company X has 50% licensed, whereas Y has 20% licensed, most clients will choose company X.
Companies will not only pay more for licensed professionals, but they will often times
pay you to become one. Also, the typical cost for stamping an engineering drawing, if contracted, is around a
minimum of $1000 (usually more, since almost all places require the PE to be intimately involved in the drawings production).
Many smaller companies don't like liability (for good reason), so they'll pay good money to get a PE to do, review and sign off on their designs.
Most PE's recouperate their losses, if not directly through contracts, then indirectly through pay.
Though, as it applies to someone working from home, yea I suppose it'd be a tough going if you only stamped drawings. But in my mind, there's no such thing as a work-from-home engineer.