what would of happened if the international community had recognized Republic of Zimbabwe Rhodesia and not pushed for the Lancaster House Agreement?
After the UDI, that's ASB. The only way you can really get this to work is if you have a different set of events leading up to the UDI. Not even South Africa gave full diplomatic recognition to Rhodesia, so the chances of the international community doing that are non-existant.
what would of happened if the international community had recognized Republic of Zimbabwe Rhodesia and not pushed for the Lancaster House Agreement?
It's hard to say, but I think that would have been an unstable arrangement, and would eventually have fallen apart as Blacks would not have accepted long-term the disproportionate power of the white minority. But who knows? Stranger things have worked.
i'd point out New Zealand and it's Māori seats as a case when a minority is special electoral power
Yes, but the Maori were a disenfranchised minority being assured at least minimal representation. Z-R had whites, the former imperial ruling minority, being given disproportionate power. I think that's an unstable situation, especially since the Whites will control the economy.