Australia

but then we have to do everything by weight class (like that chart i think it was you that posted?)

Not me. Someone else posted that.

But I mean, would that be the worst thing? We already do rego based on weight class, up from bikes which don't require rego to heavy trucks which pay the most.

But anyway, no, we wouldn't have to do it that way. Up until the Newman Government instituted the changes, we had a fairly sensible policy (something that could, frankly, be said about a lot of Newman's policies). Most of the world still has sensible laws in this regard.

such as blowing through a stop sign

fyi literally any expert will tell you that stop signs being treated as give way signs is far better for safety than actually trying to enforce stop sign laws for cyclists. It's called the "Idaho stop".

Anyway, all this "could" is all well and good, but our policies should be based in evidence. There's no evidence to suggest that it's either necessary or helpful.