i dont know much about ingrown quills since i've never dealt with them, but a year does seem like a long time to have a bump :/ hopefully your little thistle gets better soon :D
I found this photo of someone who was pretty sure what they were dealing with was an ingrown quill but i can't be sure! its probably best to have a vet take a look at it, as it could be something very dangerous.
My hedgehog hadn't been fed anything but her kibble before I got her so she was resistant to try veggies and meal worms. However, I learned that if I cut the vegetable in a really small size (no bigger than her own food) she tried it and loved it! now she will try to eat them at any size...
I would recommend just scooping him up with a towel and sitting with him on your lap for about 15-30 minutess when you sit down, maybe to watch tv. It would probably be best if it was dim and quiet.
I've handled my hedgehog for at least a few minutes a day and she definitely isn't scared like...