Here is some answer for you.
1. Firstly the APS-C sensor Canon 50D with the Tokina at 12mm will give you approximately 63 degrees HFOV. So this requires 8 rotational images to complete the full 360 degrees with decent 20+ degrees of overlap. You will require 3 rows 0, -45 and +45 and a Zenith/Up, Nadir/Down shot if my rough calculations are right.
Your images show you have not "nailed" the NPP (no parallax position) and you need to take more care setting up your panohead. Here are two examples where parallax is evident in your panorama.
These areas should show no parallax between the same areas. This is sure indicator that your panohead/camera position needs attention and is the likely cause of stitching errors and misalignments. More help on this in this thread.
2. I teach all things panorama on a "One on One" basis. No set coarse, we work through things as necessary.
I will contact you privately.