I think this is a great idea.
Makes sense to be able to chose whether or not you want your info visible on the data base, and to be able to change this manually as and whenever you want to.
I wouldnt expect it to generate floods of novel requests for help, as info about each of us, what we do and our contact details is already readily available to anyone who has a bit of a google.
If there was a ‘free-text’ section that members could complete in their profile then this could include more detail about what individuals would be willing to offer/share/collaborate at the present time to support young researchers etc.
Best wishes, Kate