Tenant asked to move her fiance in which I approved.  1- Should I have them sign a new lease or should I do a renewal and add him to it?   

And should there be any slowing down of the single family market, commercial assets, particularly in sectors such as multifamily, self storage, and mobile home parks, tend to be less correlated to the market sentiment, thereby further insulating investors from market downturns.

You should be able to negotiate a sale and have your parents sign the paperwork with a mobile notary present.

But it's not illegal or an ethics violation if done with the correct approval.  

I trust my management company but I always approve anything over $100 before they spend my money on it.  

Sorry I don't have any insight into the NoVA Section 8 market but I know the approved rents in the District are extremely high but I do have a question that will hopefully help you out as well...Does the DC Housing Authority do a market analysis on comparable rentals in the area before they agree to pay the amount listed on the website or are the rent amounts listed on the DC Housing Authority what investors are typically getting? 

They applied for an additional three months of extra rent and we just received approval for that.

Should I keep looking at deals if I come across a smoking deal do I present it to a investor or a loan officer and see if i can get pre approved, what do you guys think? 

They may only approve the tenant for 2K even if they have a voucher for 2.3K. 

As a lender, I see this as completely bait and switch unless they provided you a solid reason regarding the approval.