@Kelly Carter
Lots of great advice here. I 100% agree with @Russell Brazil on the 1% rule for the type of property you're looking at (as well as his comment regarding different returns on different properties). I just posted the other day about how I really don't agree with a lot of the financial "rules" that people here use for properties but I generally agree with the 1% rule in your price range and neighborhood class.
I have a property that I purchased at $134k and rent for $1325, I put the traditional 20% down, and there is plenty of cashflow.
No offense but I don't think a flip would be right for you at this point just based off your post and profile. It requires more knowledge, time, work, and connections than you might have right now.
It might be worth following up on the properties your real estate agent says will go for 25% over asking and seeing what they actually sell for. Is he being realistic or is he trying to get you to put in some offers so he can make commission?
Regarding your math, I think that 8% vacancy is conservative but I don't find it unfathomable. Based on your numbers you are putting in an average of $246 per month into the property. Does that sound right to you based on the types of properties you're looking at? Again I think it's conservative but to each their own. I wouldn't get rid of the management fee when calculating, in fact I'm surprised it's not 10%.
Keep looking, know your market very well, and when a good deal comes up you'll know it right away and can jump on it.