Welcome back, aelf! I don't know how I've missed this thread for so long. Good to see you're giving Mehmed a chance after his ignoble fate at my hands. Shaka would be a lousy tech partner, but a formidable war ally, so wiping him out completely or making him a vassal depends on what you want to do about Genghis. If you plan on conquering the Mongols soon after finishing the Zulus, you may want Shaka as a vassal; he should be able to distract Genghis at the very least. That being said, I'd be tempted to wipe the Zulus out completely. That way you don't get an automatic -1 diplo hit when you meet the other civs. And he has some very nice land. As for the next tech after CS, it seems kind of obvious to me: go after Machinery, Engineering, and Guilds to amass the techs needed for a medieval army. Meanwhile, tech towards Liberalism using Great Library-generated Great Scientists. I wouldn't take Gunpowder from Liberalism--it's too cheap--but you'll want to bee-line to it sometime in there. I'd be tempted to forgo Optics and the circumnav bonus in favour of it since it unlocks the UU.