I've said before that I think you have an unusual mix of customers compared to ours. So I am not downplaying your concern. But Shawn's (1) certainly gets in the way.
A basic installation, which if they are on 2013 and meet the rest of the system requirements is not a terrible experience. If it's structured so quite clearly you aren't responsible for anything besides making it work as Sage says it's supposed to, then I don't see how a customer who otherwise wants to stay with you will make this an reason to leave.
However, I wouldn't just turn on CRM and let them play with it. It just never comes out well as a starting point. I suspect that IT wants to play with it, and no real user is intending to. If that's the case, then this definitely will not go anywhere.
It's important that your customer knows this is not just ""another module"" like say, Bank Rec, to just turn on. Sage doesn't like to say this, but Sage CRM is a stand alone product that is linked to Sage 100. Consider this request as a cry for help from the sales & mktg part of the customer, and use it to organize some simple discovery as to what they want out of it. Maybe involve @PeterWolf in that initial discussion.