How can I delete unnecessary anchor points ALL at ONCE? (pathfinder / offset path)

Hello there, I've been trying to search answers on this topic but it was of no use...

I'm currently having troubles from having too many anchor points after "image trace" or "offset path tool".

1.  I would like to know if there's a way of deleting useless points AT ONCE. (ex. multiple anchor points on a stait line, or duplicated points at one anchor point)

    - I've tried "Simplify" but it changed the picture too much.

    - I've tried "Remove redundant points" when using "image trace" but it came out as below:

2. Sometimes pathfinder seems to make duplicated paths. Is there any way of knowing that there are duplicated paths OR eraseing duplicated paths at ONCE?

Thank-you for reading this msg, I hope to hear from anyone who has answers to my questions.