I agree with the others -- to get out to the Paddler's Inn and back (assuming you're going from Telegraph Cove), you'd likely need more time than five days unless you plan to water taxi at least one direction. If you do paddle from Telegraph Cove, you will need to cross Johnstone Strait and as has been said, it's not a crossing for paddlers with little experience -- it's a stretch of water that can be very difficult to paddle if you don't hit it right.
Bruce (at the Paddler's Inn) has a charter service with a well-equipped kayak-carrying boat
-- and his prices are quite reasonable (I believe he's soon going to be doing a regular scheduled run twice a week from Telegraph Cove). I'd suggest meeting up with him on the first part of your trip -- he's a wealth of information about the area and could likely save you a lot of time finding what your cousin is looking for.
Not far (about 2km) from the Paddler's Inn is the Raincoast Research Society -- an ocean laboratory that mostly studies salmon -- your cousin might find it interesting as there are several marine biologists conducting studies there.
If you're camping, there's a really nice campsite on one of the north-eastern islands in the Burdwood Group. No fresh water but it's a beautiful spot.
I've paddled in that area three times now and will be heading there two weeks from tomorrow for three weeks. It's a fabulous part of the BC coast.