1. This may be caused by an axis-system mismatch. Did you properly setup your PopcornFX project with a left-hand-Y-up axis system?
2. This is by design. Scaling particle effects is a non-trivial problem as it is unclear what a difference in scale might mean (change in emission rate? Particle size over time? What about the life duration of the particles?).
So yeah, it's up to the developer to implement attributes in their effects to control these aspects.
3. Indeed, this is a limitation due to Unity's native plugin interface in conjunction with the command buffers and the fact that we render our particles from the native side.
We are currently working on a solution to move the rendering over to Unity's side, which should solve this problem.
4. See 1.
Sorry to hear you feel cheated by our Unity plugin.
I'd like to point out that we do have a support email which can be found on all our packages pages on the asset store :
We do provide support for all our products via email or this answerhub, paid plans mainly guarantee short answer delays and dedicated time.
If you are dissatisfied with your purchase and the responsiveness of our free support and would like a refund, you can send us an email with your invoice number and we'll ask the asset store to issue one. No need for threats.