Hi there,
Congratulations on your success thus far. I'm impressed!
Regarding the herbs, absolutely you can keep those doses down at the minimum level required for efficacy. That way you have room to go up later if need be.
For vitamin A and D, since things are going well, there's probably no reason to dose too high. I'd use it weekly by mouth, but I use the injectable preparations to make my oral doses from. I dose for vitamin A, and quite high as you know - about 5000 IU per lb, to a maximum dose of 500,000 IU of vitamin A. The vitamin D is D3, so at weekly dosing, the risk of hypercalcemia, and even hypervitaminosis A, is slim to none. After a month or two, you can drop down to monthly doses by mouth if things are still stable. I don't recommend repeat injections of the parenteral preparations. They tend to cause type I hypersensitivities, hives in particular, when injected more than once.
Continued good luck. I'm sure your success will be an inspiration for others.
Steve