Sorry, but why not just use phpredis? We heavily use Redis + PHP, and phpredis already seems to be a fairly minimalist interpretation, in the sense that it doesn't attempt to implement commands that Redis doesn't support. It's also written as a C extension, which makes it, to my knowledge, the faster PHP Redis client out there.

Also, using magic methods tends to be about 3x slower than a normal function call, AFAIK.