How is the Shifter on it’s own, and can it be made to work?

[Mara]

You would advocate for a very nice houserule then. As written, Oozeform is undeniably a part of Fluidic Body. If it wasn't, it would have its own class feature entry and not be part of Fluidic Body.

And now you are ignoring the Polymorph general rules and dev intent.

You have to do SOMETHING uncouth to get the archetype working.