You may also decide to simplify the skeleton and remove the chain of bones if it's not going to move much from this position (If it does, it's good to keep the chain). Here's an example of a similar possible setup:
Loading Image
And here's more about the bag in the example project it originates from:
Mix and Match example: Bag
If you can, start with a straight image of a tube. If you want to keep the chain weighted to a path, that's a good idea when you need to heavily manipulate the path. I noticed your image bends a bit weirdly at the tube lowest and most bent part. Don't forget you can smooth the weights or add just a couple vertices there to make it look better:
Weights - Spine User Guide: Smooth