I will share my advice from one noob to another. I'm doing my first flip in richardson, tx. and I have learned a LOT.
You need to get real comps(idk if you did or not). Get a contractor to give you a rehab estimate. They will come for free--just make sure you are respectful about them giving you their time and entertain the idea of using them for the project. Ideally, you would even get 2 or 3 of them to come. Stop using Zillow for comps or values of any kind. I use them to look for photos and taxes and that's it. So make friends with a realtor that values working with an investor. One that knows you'll be buying and selling a lot of houses in the future instead of just one house and then he has to find a new client. A good realtor will get comps for you within a few hours or less. If it is taking them until the next day, get a new one.
As for paying cash or not, and whether you should do the rehab or not, can all be determined by crunching numbers. The cash thing depends--if you can get a super low interest rate, and the rent is covering your costs, then you will save some of your cash for another deal. On the other hand, if you see that paying all cash takes out interest and loan origination costs, and increases your cash flow, then maybe that is better. And you ought to do only one deal at a time anyway, so you don't need that cash.
As for doing the rehab, you'll have to see if the money you put in, and getting $1200 a month, is a better return on your money or not. And you want to be absolutely certain that $1200 is accurate. My parents and I bought a house in Lubbock expecting it to rent for $1200 and it rented for $950. It really turned the deal into a turd.
Conclusion, learn how to crunch the numbers. It is a must.