Depending on how the Node handles volume normalization, it may be advisable to dial in -2..-3 dB there.
The Ref Level setting closest to 2 Vrms on the RME is +7 dBu (~1.73 Vrms).
This setup offers more than enough settings to be thoroughly confusing.
Notably, the Yamaha offers:
* volume
* input level trim (mainly intended to get multiple different sources to a similar level)
* loudness (presumably Yamaha style, i.e. loudness knob becomes main volume knob once in use)
while the RME has
* volume
* loudness (custom, tied to volume setting,
here's an alternative approach to setting it up)
In case this was not clear, the point of a loudness function is counteracting Fletcher-Munson with EQ so that things
subjectively keep sounding the same at different volume levels. In traditional hi-fi (except Yamaha) this was usually tied to volume pot setting, which rarely works the way it is supposed to unless input level happens to be exactly what the equipment designer intended.
You should probably decide between using either the RME's facilities with the Yamaha being a dumb power amp, or the Yamaha's facilities with the RME being a dumb line-level DAC. The former variant may exhibit too much output noise once the Yamaha is turned up far enough to cover maximum volume needs, but trying it won't cost you anything. The RME is easily good enough to drive a pure power amp directly.