I'm sure some people on here will know the answers, but I think the best bet would just be to call an registry office and ask them. Or go in and they might be able to sort things out for you then and there. Same with insurance.
I'm also not sure of that temporary registration thing you mentioned (When I had purchased mine we met near a registry so it alleviated the problem).
anyways, from the AB website:
To register all new or used vehicles or trailers, the following is required:
- proof of ownership, such as a bill of sale or lease agreement
- proof of valid Alberta insurance, (not required when registering a trailer)
- two pieces of identification or an Alberta Operator's licence
- vehicles imported into Canada require a Vehicle Import Form obtained from Transport Canada
- an inspection certificate from Alberta Infrastructure is required for all first time Alberta registrations of used vehicles
- the vehicle must be in Alberta
- letter of authorization if someone is acting on your behalf
If you currently have valid Alberta licence plates in your name, you may transfer them to the new vehicle.
I couldn't find a link specific to Alberta, but here's one that has to deal with the buyer/seller responsibilities for Ontario (keep in mind some are Ontario-specific)
scroll to "A Buyer's Checklist:"