To your question about the warmup, even a small amount (whatever you can do in 5-10 minutes) is good, when done consistently over a long period of time. Just make sure that you're not rushing when you do them. If you're aiming to fill a complete page, rather than aiming to do the best of your current ability with the time you're given, then your warmup won't be as effective. Don't worry about how much you can cram into that time - focus on doing it as well as you can.

To your other questions:

A. This is correct. Just to confirm that point, I used a 3D modeling software to get some cylinders at different rates of foreshortening and plotted out the minor axes on top of them, along with the vanishing point for that dimension here. Once we get into truly extreme foreshortening (which we wouldn't really use that often in our own drawings), the rule breaks down, showing that it is indeed an approximation. That said, I would still apply that rule for two reasons:

• It still looks correct even at high rates of foreshortening, to have your minor axis align to the vanishing point. That is, frankly, far more important than something being actually correct, in the context of drawing and illustration.

• Breaking things down into simple rules that can be applied when quickly generating designs (where we don't have the time nor focus to expend on plotting things) allows us to work more purposely towards the end goal. There are definitely artists whose work requires highly technical and specifically correct perspective, but those are cases where the drawings are used for architecture, engineering, etc. For the rest of us, in illustration, concept art, and so on, using rules like this that are "close enough" but allow us to work quickly without any obvious errors to the naked eye are far more useful.

B. I don't fully understand what you're asking here, your wording is a bit confusing. But I can say that yes, the minor and major axes are independent of what you're doing with the contact points, at least for the most part. The major axis is entirely irrelevant here, so we don't even worry about it at all. The minor axis, however, aligns to the dimension coming off the surface of the plane, whereas the contact point lines define the two dimensions that run along the surface of the plane, as shown here.

C. If I have written it into the instructions, then it is something I allow. If I allow it, then it is equally valid as any of the other allowable choices, unless explicitly stated. I find Lesson 6 and 7 benefit especially from the freedom to use ballpoints, due to how those lessons result in much more construction and subdivision of forms. It is the same way I allow for the use of a ruler and ellipse guide here - I don't want students to get distracted needlessly by the things that earlier exercises and lessons address.

That said, do not use a different colour for your construction and then go back over it with black. The same rule applies if you're using ballpoint - you should not be drawing back over your construction as a sort of clean-up pass. Everything should be drawn with the same kind of pen, and line weight should be used in key areas to help clarify overlaps, but not to redraw your lines fully. You can look back at the form intersections from lesson 2, there are notes there about not using an underdrawing/clean-up pass.