Welcome to the Daily Puppy from Oliver & Henry, and their Mum, in London, Ontario.
It's rather difficult to tell what sort of mix you may have. You did say that a "Vet Assistant" looked at her. I do hope, considering all of the issues you say she has, that she has been thoroughly vetted. If not, you really should have her checked out as quickly as possible, particularly for parasites, as well as to make sure she is up to date with her vaccinations.
A Vet should be able to tell you far more about her mix than we can with the photos, at least at this age. You also described scabs around her neck which could be indicative of Mange or a skin parasite such as ringworm. I can't stress enough how important it is that you have this puppy checked out thoroughly.
Kudos to you for rescuing Mishka! Do let us know how you make out at the Vet's.