Sorry - a couple more rules clarifications that I hope you won't mind advising on...
1) Can you react to a grenade before it explodes? It seems like this is the intent but I can't see it saying that anywhere. Plus just to check I've got it right if you see the model throw the grenade you react normally if you only see the grenade you can only dive out of the way?
2) can the grabber slasher do its jump in close combat attack as a reaction if it is not in overwatch?

Thanks in advance