Q1:

I do know how state detectors go in general for x bit number, like to detect sequences of 0111, 010, etc (overlap or without overlapping), but I haven't learned how to detect odd/even number of 1s or 0s.

I have tried Youtubing but no help.

Firstly, I'm not sure how to make it for arbitrary bits. (Like max is 8, and there can be any from 1 to 8)

Secondly, I have no idea how the working goes for it too.

Here is my attempt for 3-bit version of the question, I think I got everything wrong.

(Apologies for my camera) (G and F go back to A)

Q2:

Here is my attempt:

https://pasteboard.co/IfgXuya.jpg (can't get image tags to work)

Is this alright?