Same day rush service: additional fee of $30 for 1 working day processing (applications presented

Same day rush service. Does that mean for an extra 30 dollars I can submit my application of 2 people and get it the same day? No haven't to come back another day later on?

If I get there by no later than at least 10 am or 9:30 am? Will I be able to pick up my passport with a visa by then, by noon or later? Can I just wait for it to process or do I have to come back at a later time that very same day? I am wanting to do it all in one day and not have to come back another day or get a hotel since i live in NC.

Also, we are traveling to China to visit friends. And we will be staying with friends. Do we actually need an invitation letter from them? They are US citizens themselves and living in china on a work visa themselves. Do we just need their address and nothing else?

Can you be specific on things?

Do you recommend a courrier service in d.c. for us citizens for a 10 year chinese tourist L? Because that is what we will be applying for.

Thank you,

Sorry for all the questions.