researchers with a Home Organisation (that operates or potentially operates an IdP)?
citizen scientists?
students students with a Home Organisation (that operates or potentially operates an IdP)?
else/what?

3.Questions on Identity and Authentication

User's "network identity" distinguishes him/her from other users of the SP.

3.1. Identity concept

How important is it

...

for you

...

that

all account identities/accounts belongs to an individual person (i.e. there are no shared accounts like "libraryuser1")?
and all users are traceable (i.e. the home organization knows and can reach him/her)?
and Home Organisation is willing to collaborate with you if their user misbehaves?
that you (as an SP) can block him/her from your services?

...