1. How can I move the shapes to the left of the description?
This can be done, but requires some pretty sophisticated (i.e. Jedi-level) techniques. See Older But Still Useful – Conditional Formatting | Drawing with Numbers details.
2. How can I get rid of the columns that include Week, Day, Descript with Time on top?
Are you really wanting to remove the columns? That seems to contradict #1. If you want the column value for grouping or sorting, but want to hide it, click the pill menu, and uncheck "Show Header." If you are wanting to hide the labels for the columns, right-click on the header, and select "Hide Field Labels for Rows."
3. Shading the week rows along with other grey columns doesn't seem to work. How can include them as well?
The Row Banding is controlled by Formatting. Right-click in a column, and select Format. In the format toolbar:
Select the paint bucket tool at the top. Then, in the Row Banding section, adjust the Level as desired. The Level corresponds to the dimension columns in the view.
I hope that helps.