Hi,
I am a novice in UE4 blueprinting. Hoping to get some answers 
I love blueprints so far, but how much freedom do I have to create my own UI with my own graphics?
Is it possible to get a transparent image to act as a button with mouse hover?
Is it possible to have an animated image / video as the background?
Is it possible to create a custom staminabar, healthbar, "loading"bar, countdown ect? (Self-created images only).
/Total
There is however it takes a lot of patients to do the last one. UE4 has made videos for there introduction to third person playlist describing how to do it I believe. I know its in one of their intro to… videos. The last one is really tricky and there are multiple ways to do it I would recommend goggling it which will take you to the UE4 how to PDF thingy which is easy but long. Sorry I couldn’t give you step by step directions. I don’t remember it by heart.