What would be the best percentage to use when analyzing income,expense,prop value increase? 

Not many realize but a lot of them are on fixed income from year to year so they face challenges with costs going up every year.It should also be a lucrative business with the increase in population of the elderly in the future.Good luck with everything!

Which is what is super appealing to me especially if it needs some work that can increase the value.

Focus on the long game.If I were in your shoes, I'd be thinking about increasing my portfolio (1 unit to 2-3 units). 

The simple answer is an increase in the interest rate!

Both areas also, with the exception of the financial crisis, have consistently increasing property values.

HUD prefers 60 days, but mine can do 40 or so and be fine.I send a regular notice of rent increase to the tenant and e-mail their caseworker as well.

On the one hand you can see that on the day the transaction was completed they got all The money that was due to them based on the facts of that point, going forward they are not the owners of the house anymore so if we got a tax credit or a tax increase it does not really concern them, on the other hand you could say that they took the effort to do this and since that credit was applied to the year they sold the house they should have a prorated amount based on the months they lived in this house.The second question is why didn't the sellers lawyer contact us directly, as the lawyer we used for the transaction is not really working for us on a regular basis and is not our regular counsellor.

The best way to optimize a profit and increase return to the owner would be to partner.

(i.e. not having to worry about rate increases every 3-5 years).