In reverse order...
Rings is the resonator section from Elements. So, yes...and more besides.
Using an ES interface as a VCA in conjunction with a DAW is...well, sort of a waste. For example, let's say you plan to do this anyway. So, what has to happen is that your signal has to go to the ES's input, go through the conversion routine, get transmitted back to the DAW, processed in some way by the DAW to control the level, go back out to the interface and get REconverted back to analog, then back into the patch. Which brings in all sorts of ugly factors such as latency, digital jitter, etc etc. Plus, you're using some expensive jacks there to do what a basic, inexpensive VCA module does. And even if you wind up controlling that VCA via Silent Way, you're still using only one output channel for that function, and there's no encode/decode/latency/jitter issues. That's really how the ES interfaces should work; the input channels really work best in a send-only method, for either audio to stripe to the DAW, or to send clocking, etc data.
In theory, you can send audio to the modular via an ES interface (basically, it's a DC-coupled audio interface) from your DAW. But if I remember right, you'll have to have Ableton address the interface as if it were an audio output, and Silent Way wouldn't enter into this part of communication. However, given the nature of analog modular synthesis, you might be better off using a proper audio input module that also has an envelope follower, as that last device there can be very useful in shaping other CVable factors (especially timbre and dynamics) by using the audio level of the input signal. Setting that sort of thing up in the computer might actually wind up being a lot more fussy and unintuitive than the few patches and knobtwiddles that the modular solution would allow.