The only bit of advice I'd give is - I don't believe it's a good idea for him to come along on many of your command navs. There's a large difference between being PIC with an experienced pilot next to you, and being alone in the plane (or the only pilot). You need to get completely used to the feeling of flying alone, and not having anybody there to assist should you require it.
Most guys here would have felt that slightly empty feeling when something's going slightly wrong (weather, equipment, disoriented approach/nav etc.) and for the first time, you've got nobody to chat to and discuss a course of action with. If you've got a G1 sitting next to you on lots of command flights - you're not getting the true command experience, as you'll have the feeling of security that he'll be there if you really stuff something up. Just my opinion, but I feel that training-wise this is pretty much a dual nav where the instructor says "ok you know what you're doing - I'm not going to say a word on this flight, I want to see you do everything".