I'm currently CX Marco Polo Gold (1w Sapphire)...I haven't been doing that much travel within the last few months (or mostly with KA that don't count towards Marco Polo anymore)...I'm now trying to see if I can use a 1w explorer ticket to get enough flights to renew my status for next year (membership year ending in June)...since I usually qualify by using "number of segments"...I want to get as many as flights as possible, as allowed by the 1w ticket...since I haven't flown with AA at all before and am not too sure about their domestic network, I hope that some of the experts here can help me out with the planning...

I'm thinking about a 3-continent 1w explorer in business...so on domestic US flights I can get first class if business is not available...since first class counts as 1.5 segments and business is 1.25, I want to get as many flights in first class as possible (although I know, for example, premium transcontinental business class is much better than first class in 2-class)...I think the max number of segments within North America is 6 and within Europe is 4...

I don't have specific dates set yet, but I'm thinking about leaving HKG after work on a Friday, and I need to take the LHR-ORY flight Sunday evening...

My current plan is:
CX 872 - HKG 23:20 (Fri) - SFO 21:05 (Fri)
AA 1992 - SFO 0:15 (Sat) - DFW 5:29 (Sat)
AA 516 - DFW 6:45 (Sat) - AUS 7:37 (Sat)
AA 61 - AUS 8:35 (Sat) - DFW 9:37 (Sat)
AA 90 - DFW 10:30 (Sat) - ORD 12:47 (Sat)
AA 650 - ORD 13:30 (Sat) - BOS 17:00 (Sat)
AA 1244 - BOS 19:30 (Sat) - JFK 20:48 (Sat)
BA 116 - JFK 22:00 (Sat) - LHR 10:00 (Sun)
BA XX - LHR - XXX
BA XX - XXX - LHR
BA 338 - LHR 18:30 (Sun) - ORY 20:45 (Sun)
then a few days later...
BA 339 - ORY - LHR
CX 250/254 - LHR - HKG

My questions are:

1. Time for connection: in most cases I have around an hour between the flights in US...is this enough ? how's the on-time performance for AA in general ? Since I am taking so many flights in a day, I think I will have very high risks missing connections...or is it in general better/worse on Saturdays ??

2. I have not included any American Eagle flight in the itinerary because I am not too sure whether they have first class or not...are they more like United Express (coach only) or United Shuttle (with first class) ?

3. Do you have better suggestions for the routing...basically I want to maximize the number of segments (and keep in mind first is 1.5 and business is 1.25), so that means I prefer connections/short flights...

4. For the few hours in LHR on Sunday (BA XX in the above itinerary), I'm thinking about a same-day roundtrip to a certain destination...is there a good option for this ? And, in fact is it ok for me to transit through LHR 3 times with a 1w explorer ticket (but no stopover at all) ??

5. For the last LHR-HKG segment, is it ok for me to do LHR-SIN (on BA) then connecting to SIN-HKG (on CX) (which adds another 1.25 segment) ?? What is the rule in general about flights in the continent of origin ??

Thank you in advance for your advice !! Please let me know as well if you have other thoughts...thanks !!