Shop around for commercial portfolio lenders.

I would tell them to provide the appraisal ASAP and I will be shopping around.

As many know, there is always something unexpected or new to learn right around the corner with real estate investing and it can be stressful especially without a mentor or colleagues to talk to.This site is truly a one stop shop for real estate investing. 

Shop around, ask questions, and make sure you're getting quality work.  

One is "a family of 3 with my uncle is a small business owner,i'm a manager at a billard/coffee shop and my uncle's daughter(an international student)", the other two are "I am looking for a place to live for myself and two other friends.

An owner occupant who is shopping for a 50k home will be hard pressed to come up with an additional 400/mo for fees, so you'll probably be looking at a sale to another investor.That said, it always comes down to what's happening in your market and what part of a cycle you are in.

They do this in part to know that you are serious and not just shopping around.

Line up your hard money before you go shopping.

So to summarize, do I need to use different proof of funds on every offer I give or can I go "shopping" using only one?

I have found if you have a good shopping list.