thanks for all the advice. I got the achievement, and it was rather straightforward. I went South as most suggested, and eventually moved the Capital to Kilwa. I stopped playing in 1620, and put it on speed 5 and baby sat the game till 1700.
Few takeaways from the run:
- there is a known bug in the current patch that sometimes prevents you from getting merchants from Trade companies. It is not a problem because yemen gets 2 extra merchants ( from Shafi'i school and NIs).
-the first 3 institutions were very difficult to get (all obtained via adjacency from Medina to the north). So absolutely cannot afford to take a military idea till much later, otherwise you will fall behind in mil tech.
-Exploration+Expansion as first 2 ideas worked very well in closing off the Cape and South Africa completely. In addition, I colonized all Indian ocean islands and St Helena, making it impossible for Euros to colonize in it until much later . The first European I saw in the East was Portugal in Tasmania in 1685. By then it was over.
-the final threat to the run would be the Ottomans ( whose capital is in Europe) taking one of the coffee provinces in Ethiopia or Yemen proper. In this patch they do not steamroll like before, so this was not a big deal. I managed to remain their ally throughout. One thing that helped is that I stopped expanding in 1620, and so I was below them in rival level and they did not break the alliance with me.
Last screenshot of the game in 1700. Ottos had just called me into a war against Makuria:
One thing I noticed is that you do not need to fully core your capital when you move. Saved me about 150 ADM at the time.