1. Technically no. But I think you might be able to convince them to do it since you have no other alternative.

2. *2 permitted in Europe to/from/via ghana/nigeria. 1 must be a transit without stopover between Ghana/Nigeria and another continent.*

Otherwise the rule is clear that there is only one continental arrival and departure.

What you could *possibly* do is lax-lon-los-lon-cpt, if you didn't stopover in London. But you would run into a situation that you would lose all your stopovers and segments in Europe in order to stop in Lagos or Accra. Maybe I am not seeing it, but I still don't see how you can go to MRU, SEZ, DAR or NBO anymore.

3. It isn't a one way flight. It is a flight with three transits that only retains a single flight number in one direction. There are many, many of them.