Ue4 Questions

Hi i just started UE 4 and have some questions:
1)is there a fluid actor in UE 4 as there was in UDK. I don’t think this is implementable using cascade, no? or would i have to write my own Fluid Simulation?

2)How to spawn a UParticleSystemComponent using c++ because i get a weird error about it not being able to convert to a *UObject


UPROPERTY(VisibleAnywhere, EditAnywhere,Category = "Particle System")
	TSubobjectPtr<UParticleSystemComponent> FireSystem;

3)Is it possible to edit the terrain during runtime? using c++ preferably

TSubobjectPtr its deprecated use a regular c++ ptr. i.e:
UParticleSystemComponent *FireSystem;