Oil Barrage feedback

I have build entirely around Oil Barrage and theres few issues:

1/ For some weird reason its unable to shoot uphill. Its frustrating, any slight bump just block it. Even stairs block it. Maps like Willow are terrible experience.
2/ It gets cockblocked by desttroyable objects (like pots) as it doesnt break them
3/ It has issues with hitting target in melee range, even if it literaly hugs your face.