I agree with the following (too lazy to look back to see who said it):
- A1's sub shoots FTs for B1's personal foul
- A? shoots FTs for B1's T.
- Ball at division line for team A
Reason: Most rules, unless stated otherwise assume there are no complicating issues. They're not going to spell out all the possible cross-products of the rules. If they did, the book would be thousands of pages. We're expected to understand the intent of the rule. As for POI, it means do what would have been done as if the double/simultaneous foul had not been called.