Greetings.
Concerning the relation between typing and playing piano, I am not too sure, but in my opinion, there is very little correlation. Both use different skills, and different movements. I think it is very similar to ther reading sentences and reading notes. Both are completely different and having experience in reading lingual text is not going to help you with reading musical text. As a proof, certain pianists have been reading notes before they could read, so that confirms that reading literature and reading music are two independent skills.