Nice work.
For smaller blades hand tools have some advantages, they make no noise and much less mess and as long as you have reasonable timber it can be nearly as quick. When you get up into the big stuff then roughing out with a chain saw seems the easiest way but even at 10ft you can still do it by hand.
If those discs are the 1/8" ones I replied to elsewhere then yes they are too thin. I hope you didn't use the spokeshave on them.
The hub looks excellent for the job. You look to be making a really nice job and if you are struggling with the discs I think you may be better buying them rather than compromising some otherwise excellent work.
Flux