Hi. I am hoping someone could answer a few questions regarding a planned trip from ATL -> Europe (undecided as to location, but probably FCO) using American Airlines rewards.

I looked at the route map for AA. American Airlines does not fly direct to Europe from ATL except for flights using British Airways planes (from what I gather), which fly directly to London.
If I wanted to fly AA to Europe without taking a BA plane, I would go ATL->MIA->London/Paris/Barcelona/Frankfurt OR ATL->JFK->wherever. But, I looked on Kayak and it seems like every flight from ATL that I could purchase goes directly ATL->LHR, using BA. I am nervous because I am aware BA has very high fees (although apparently a great First Class product and a nice Stopover deal).

With this in mind..
1) Would I be able to stopover in LHR if I wanted? (The issue is obviously that BA permits stopovers and AA only permits domestic stopovers) (assume I want to ultimately fly ATL->FCO with stopover in LHR)
2) I suspect I will have about 160k in AA rewards. If I want to book an AA flight, will those AA flights using BA planes count as AA flights or as Oneworld partner flights? More importantly, will I be paying BA fees or AA fees?
3) It looks like I can get a 50k MilesSAAver flight or a 100k AAnytime flight (each 1-way) for first/business. Obviously I'd prefer to have two 50k flights. With effort, what is my likelihood of booking 1 MileSAAver flight? 2 MileSAAver flights about 9 days apart? (I plan to fly in either May or Sept, although perhaps if it's reasonable to expect availability, I could do a summer flight)
4) In an effort to avoid fees and book at the lowest possible points, about how many weeks/months in advance should I book my flights?
5) What are the estimated fees/taxes for booking these awards? What can I do (/read) to reduce these fees?

The next set of questions has to do with my plan for my return leg to be something like: CDG -> MIA (stop) -> HNL ("holding" the MIA -> HNL first class flight). I would then fly coach with 10k United points from MIA -> ATL and then fly back ATL -> MIA at some later date and take my first class flight to HNL. Then I pay for my return flight HNL -> ATL with points. (It looks like this really only saves about 22.5k miles, but I'll take them!)
6) This is permitted, right? (specifically, the stop in MIA)
7) I will likely have no idea when I can make my HNL flight. What kind of rebooking fees am I looking at? How many months can I confidently expect to push it back? (e.g., I might delay it for 9 months)

8) Finally, I plan to make both trips entirely on AA miles and (probably) Marriott points (and Chase points converted to Continental/United or Marriott). Is there anything I can do to take some "credit?" I realize I am paying almost nothing and I don't think I deserve anything by any means, but I'll still take anything I can get (e.g., somehow recursively pick up more miles, increase stays for Elite status, get cash back, etc).

9) Any general advice?

That was a lot. If you know the answer to less than all of the questions, I'd still be happy to hear it! Thanks so much!