The question isn't so much about fit, but about the pros and cons of
touring boots or similar - I know many guides, including some of the
ones that can ski, use touring/mountaneering boots all the time, but
I'm not sure if it'll ruin my skiing.


Ah ok! Your shells are 7 years old, past few years they have been able to
keep lateral stiffness in boots for carving and added soft plastics in
other areas, so maybe modern, step down from race boots would suit you now?

regards,

Greg