VirtualBox's virtual machine only supports DirectX 8/9, Drakan uses DirectX 6.1. I don't have Mac neither so I can't give precise instructions, you could try setting up WINE on your machine then run Drakan through that, performance won't be optimal though. You'd probably need to decrease Max Fog Depth in graphics options significantly just to get decent frame rate, at least that was my experience with WINE on Linux.
The only way to get the best performance in Drakan is to run it under Windows host, so you'd have to dual boot, if that's a possibility, but yeah, it's inconvenient...
You need to install 445 Patch before applying AiO Patch. The "Drakan SDB" entry appears under Programs and Features, though from the other message you got, it seems it installed, so you don't have to do anything afterwards. The said entry is just another way to remove that database if needed. Also, if you decide to give WINE a shot, InstallSDB.bat and Disable_Drakan_Compat_Shims.reg aren't needed, there is Drakan_Wine_Settings.reg instead.
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