I would also personally help someone out for free, but perhaps if you turn a good profit, and this person is helpful, you get them a nice gift card upon completion of the sale as a friendly gesture.

When I went through FHA, I was told I needed 3% and found out that 1.5% can be a gift from a friend or family member as long as you agree that it's not a loan.

It is not a "gift", they want their share of the income and appreciation when we decide to sell. 

A couple of problems.You are Not allowed to borrow your down payment on a FHA, and your down payment money source has to be verified/seasoned....in your account for 2 months prior to closing, unless it is a gift from a family member only.Any additional debt payments you take on would have to be calculated into your DTI, to still qualify for the loan.  

Even then there's pitfalls you need to watch out for.A better option might be to work with your accountant and explore some gifting scenarios or contribution of assets to a 3rd party corporate entity which ends up being in your sole possession.

Even if they have been in the house for 9 months, 12 months or 18 months, there is probably going to be more damage than you may think as opposed to higher-end properties.When many of my tenants vacated my lower income properties, they would tend to take parting gifts like electrical wiring, appliances and air conditioning units.

Are you a gifted data cruncher and love spending 40/hours a week analyzing properties?

Big gifts usually involve difficulties.

I wanted to submit an offer to the agent for 21k which i would come up with from savings, gift from parents, and a personal loan(if i qualify).

Kudos to you.Bottom line though is that this is a your gift to them and perhaps by purchasing you end up reducing your long term costs then great.