I need internal circuity of pic for i/o. If pin is set to output via tris register when logic 1 pin is connected to vdd where does it connect when logic 0. Will at logic 0 pin sink current or not?
Yes, it will. That's why it's called push-pull output - output is forced either to Vdd or to Vss (ground).
And yes i know you have to limit current on the outputs. So if i have pnp emitor to vdd and base goes through 1k resistor to pic's input will it switch load on logic 0?
Yes. How big a load will depend on transistor's amplification coefficient. (For light loads, say up to 50mA, you should not need lower resistance than 4.7k - even for worst signal transistors.)