O.K. Most of this makes sense. When you say, "Card ASIO not unlocked so the host can control it" you don't mean the wordclock sync do you? I don't see another place to lock/unlock. (The other three items are fine.)

You mentioned that external control of a soft synth might be a reason for using ASIO. Anything else to be aware of? Does this include DirectX/VST plugins? I recently acquired an external controller that I haven't even hooked up yet, but I was hoping to use it to manage effects on the fly.

You can probably tell you're at the edge of my knowledge. This is where I start asking stupid questions.