You will be fine using glyphosate (Round-up) since it becomes inactive very shortly after applying it. The only problem is it should be used when the plants you are trying to kill are actively growing. I am sure it's warmer in Texas than up in New England, but I would make sure they are in fact not dormant when you apply it. Once it's all dead and you rake it up, it would be a good idea to loosen the soil to some degree, and add some good compost as well. They are many ways to do this. At the very least, you could just give the lawn a good raking with a rigid metal rake. You could core aerate with multiple passes, break up the cores, and add the compost, making sure to level it, then use the roller to compact it to a degree. If you rototill you need to make sure that you break up all the clumps really well and level the area so it doesn't get lumpy. When you do put the sod down it's important to water it every day for two weeks, and make sure it is well watered for a month after that.

Here's a link to sod installation tips from a sod farm located in my area. I have no idea about how much to charge. Link below. Here is a link that might be useful: Fulton Grass

The guy is not a landscaper - he's an opportunist. I would report him to any and all better business bureau type lists you have in town. If your state has licensing requirements, find his license number on his truck or your invoice and report him to the state agency that issues and reissues the licenses. 20 years experience is measured in many ways. Sounds like he has 1 years experience, twenty times...if that. He does have 20 years experience getting paid, though. That is evident in his knowledge of the written contract and with threats. You might try to negotiate with him. Make him understand that unless he makes this right, you will report him to every BBB list (there are some Internet based lists, too). What he needs to do will be very costly to him. He should remove the turf (and use it somewhere else immediately), level the soil surface, roll it down, relevel the surface, water it down, relevel the surface, roll it, relevel, roll it again, and then sod with a final rolling. I would not expect him to agree to anything like that. He will offer to roll it down but that won't fix it. What you might get him to agree to is lifting the sod, leveling with a drag, relaying the sod, and THEN rolling the grass down. That is what I would expect from a budget guy who tilled the soil before laying the sod. You might have to pay him more, but you really should have gone with someone else (probably more expensive) the first time. And you are correct in that it will be bumpy again as time goes on. In a way you would be much MUCH better off if he did repossess the sod. Then you could start over. But that timing sure sucks for the Derby.

As for the weed, can you photograph it and link or post the picture. Regarding leveling: At the end of a sprinkler trenching you should have a mound of soil/sod that follows the trench they dug. If that is what you have, they did it right. If you have a low spot along the trench or it is level, they did it wrong. It will take three years for the soil to settle completely. That mound today will eventually disappear. Still, I can understand how a mound could be a problem with bermuda. You might consider tamping it down now and hoping for the best. Ultimately you might be in for a serious leveling job. If you have bermuda mowed low, any imperfection stands out like a sore thumb. There was a great thread about leveling a bermuda lawn here a few weeks ago but the original poster removed his pictures. That's a cryin' shame because he really did a good job of illustrating what he did and how it looked along the way. I'll see if I can describe it... Start with bermuda turf that is actively growing in mid season, well watered, ready to be fertilized, and mowed to 3/4 inch 1. Mow down to 3/8 and remove clippings 2. Core aerate heavily and remove cores 3. Fertilize 1 pound of N per 1,000 square feet 4. Apply riversand to fill aeration holes and low places and to just cover all grass 5. Sweep sand piles around with a push broom to begin leveling 6. Continue leveling with a drag (2x4, for example) 7. Roll sand down with a water fillable roller to settle and pack sand 8. Relevel with the drag, fill with more sand, and repeat rolling 9. Water heavily to settle sand Roll again Allow grass to grow through the sand for 4 weeks. Begin to mow back down to 1/2 inch. His picture at step 4 was a picture of sand. You could not tell there was grass under the sand. I cannot be sure but I suspect that a picture at any step before step 11 would have looked like sand. I also suspect the grass blades were just sticking out when he finished step 10. In any case his grass was not smothered. I would have bet money he smothered the entire lawn, but it worked. I have been thinking about why his method worked (I have seen bermuda lawns ruined by smothering). I think the preconditions were very important along with step 3 and possibly the use of riversand rather than sharp mason's sand. I hope more people read that and will photograph and show us their results. The sand will become your new soil level and the grass will grow up through it. It HAS to be perfect when you finish with step 10 or else you repeat steps 4-10 until it is the way you want.