Help please for a newcomer!

I am planning a RTW trip using as follows

Emirates to BKK, separate ticket

Then AONE4:
BKK to SYD
7 days stopover
SYD to LAX
1 day stopover
LAX to Miami
3 days stopover
Miami to LHR
-all in Feb and March

Now comes the difficult bit. I am based in Edinburgh, and will not use the final LHR to BKK segment until October.

I am told that I cannot have more than one stopover in the same city. Is that correct? I do not see it in the rules.

If only one stopover per city is allowed, and so I cannot use Edinburgh as a hub, am I allowed to do the following:

on arrival into LHR from Miami, BA to EDI (transit at LHR, not stopover).

Weeks later, EDI to CDG, stopover, then CDG to GLA

Weeks later GLA to FRA, stopover, then FRA to Manchester

Travel to Edinburgh from GLA overland, from Manchester by BD, and from EDI to LHR with BD to connect with fligth to BKK.

I know I would have to buy 1 additional segment for this.

Is this within the rules?

Is it OK to use other BA flights, paid for separately, during a stopover period?

Do LHR and LGW count as one for stopover purposes? Are overland (or other carrier) transfers to return to a stopover point allowed. In the route desribed above, I would arrive into Manchester, but depart ex LHR

All advice much appreciated! I called BA to ask, and was told to call Trailfinders as they seem to know the rules better than BA!!