I did Bill's 2 on/2 off protocol a few months ago and liked it but it does have some limitations.
First, your frontloaded amount seems light. Check out a post Bill wrote on frontloading: "To achieve the planned steady state levels, the formula is always the same: inject on day 1 an amount which is the sum of what the usual injection would be plus the sum of what the total injections would be over the half-life of the particular drug."
Second, Bill has written extensively about 2/2 on another website and has a case study as well. You may want to read it.
Third, you may find that you don't need the Aromasin. I had a similar amount of bf% as you and didn't need an AI until I started Dbol, which brings me to:
Next, consider finding Dbol if you can. The cycle is too short to give up 3 days waiting for the prop to clear before you begin PCT. Dbol makes a great bridge during that time b/c of it's short half-life.
Next, consider changing your training if you do a typical body part split. Otherwise, you will wind up hitting each body part only twice while you're on. I used a push/pull/legs program and liked it very much. I got to hit each bodypart nearly 4 times over 2 weeks.
Next, if you do use Dbol, start the AI a couple days in advance. I waited to start Aramidex until I started the Dbol and had a hell of a time getting my sore nips under control. I had to crush my estradiol levels before it went away. Funny story: When my e2 plummets first my left wrist gets sore, then my right. They my elbows and shoulders in that order. I know I'm OK to start Dbol when my wrists and elbows are sore. If my shoulders are sore I've taken a bit too much AI. If my hips are sore, I've taken way too much. At that point, I'm so lethargic, I don't even want to train.
Next, I'd use Nolva or Clomid, no real reason for both that I've heard. Keep in mind that one of the benefits of 2/4 is the easy recovery. Get blood work done and you may find that you're fully recovered after 2 weeks, as I was. In fact, I wasn't fully supressed by the end of my cycle.
Next, I think HCG is unnecessary unless you're a belt and suspenders kind of guy. I didn't experience any testicular atrophy over 2 weeks.
Lastly, think of 2/2 or 2/4 as small pieces of a larger cycle. I think keeping 5-7 pounds after 1 cycle is not realistic. I think if you put together 3 of these cycles, it's definately possible.
Test prop is notoriously painful and you can't afford to miss workouts during a 2 week cycle because you can't even bend your leg. I cut my prop 2:1 with GSO and filtered both the GSO and the prop. I had no pain whatsoever.
Also, rotate injection spots and try to shoot into a muscle that you'll be working out that day. Seems to cut down on soreness as well.