Haecceities, strong essentiality of origins and science

1. (Premise) If essentiality of origins doesn't hold, then every particle has a haecceity.
2. (Premise) A haecceity of x is an intrinsic property of x.
3. (Premise) A haecceity of x isn't a physical property of x or a function of any physical properties of x.
4. (Premise) There is a particle each of whose intrinsic properties is a physical property or a function of physical properties.
5. Therefore, there is a particle that lacks a haecceity. (2-4)
6. Therefore, essentiality of origins holds. (1, 5)

Why believe (1)? Because if there are no haecceities then the only plausible account of transworld identity is that x in w₁ is identical with y in w₂ if and only if x and y have the same origins. And this forces essentiality of origins.
I think the problematic premise is (4). But it is still somewhat plausible.