Adventure Path and Chronicles is monthly
Companion and Modules are bi monthly
The main game they are talking 3-4 a year. Right now the two main books and screen are all coming out on top of each other cause they are the core books to play PFRPG.
As for Necro partnering with Goodman, I mean it would be a good fit but would Goodman want to? I mean they both kinda cater to the same type of fans really. I think Paizo would be a better partner for Necro, they have a well known name and despite still doing 3.5 stuff(though thats about to change) stores and distributors are still ordering and stocking their stuff. So if Necro did 4e products with them I think stores would order them.











