As Shawn says, Level 3 is not (yet) available as a home study course (although I have heard rumblings in that direction both from SFQ and I could have sworn Pete B. hinted about something coming someday from LSC also).
However, recently, the SFQ Center began selling the Level 3 manual online. The only other study materials that there have ever been for Level 3, other than the outline of the course, and course notes that come when you take the actual course or retreat, are the Sun and Moon Meditations on CD. These have been available for quite some time.
I agree with Shawn's suggestion of at least a few months of working with Level II and practicing those techniques on others before beginning Level 3 in any form.
As for most of the rest of your questions, I think that as you work with Level II, and most especially detecting blockages, you will have a better feel for how to work with things that seem less specific or at least are less of a specific area of the body.
One more specific answer to your questions, where you will see this is in your question number 1. On the DVD, on the CD's and in the manual (page 19) of Level II, you will find how to perform the Small Universe technique as part of the "Opening" stage of the healing process (also see page 16 for the entire outline of that process).
Since all conditions (ALL: including all of the things you list in your questions) are forms of energy blockage, you will need to rely more on where you feel/see/hear/intuit the blockages are, than on names, labels or diagnoses (from professional health care practitioners that is; we do not diagnose in SFQ!).
That will come as you practice and learn detection. I would rely more on this then on labels or names of conditions. However, some of the things you name are listed as connected to certain energy system (see page 21 in the manual). For example, depression is linked to the breaking system. So, once you learn how to work with that system, you very likely will help someone with depression. But again, "trust the Force, Luke" !
Rather, that than just using the charts and techniques as you would to follow a cookbook recipe. Such references can help, and your detecting will help you much more.
Once you have found where you sense the blockage to be, you use the special techniques in the Level II manual, DVD and CD's to help break up the blockages.
And most importantly, as Master Lin emphasizes again and again, is YOUR love, kindness and forgiveness with compassion. Your plugging into the Universal Unconditional Love. And then giving a strong, confident healing message, such as "memory completely normal and clear" or "depression gone, all excess energy back to the Universe, balance is restored" or whatever positive healing signal/message/information comes to you.
Although certainly technique is important, more important is practice, confidence, faith, focus and your love.
It will work and you will experience it the more you do it, I promise! It still surprises me sometimes, when it works, but it does!
Just keep practicing: on your pets, plants, family, friends, anyone who will allow you to practice on them. The more you do, the more confident you will become and it you will see it becomes less a matter of "where exactly do I point?" or "what image should I have in my mind?" and more of "wow, how did that work so fast!?!"