Answers

A Grading and Drainage certificate should have been issued by the permitting authority along with an affidavit by the contractor performing the work ensuring the work was in compliance with the approved plans.

Jie, 

Since you are not getting satisfaction from your builder, I would take all of your documentation to your city or county permit office (call ahead to determine who to speak with).  Standing water in any developement is unnaceptable and the municipality may require them to fix it. 

If the local governement can't help, contact an attorney specializing in land or propery law and ask them to send a letter to the builder.  Spending a few hundred dollars for this may go a long way. If you have to go to court, I would do so. 

My neighbors and I had sanding water and grading problems that we were able to demonstrate to the builder, and the builder came out and put drains in, no questions asked. We did not have to go to the county or hire an attorney. They recognized the problem and fixed it. 

Good Luck! 

We are moving to robotic mowers for our business location and my home. This will reduce the labor costs associated with lawn maintenance. We are also converting all of our lawn equipment to electrical. This will stop the noise, the emissions and is clean. We will keep you posted as we progress. MoBots of the Triangle is our company.

Drainage is a common issue that clients don't anticipate. 

The biggest issue we run into is not having enough black dirt (quality soil) on on hand. Trucking in more soil can add thousands of dollars, and it's not often evident at the start of construction or remodeling.

Consider what the tree is worth compared to similar trees around it. Sometimes it's best to cut down and eliminate disease spreading...

There could be infection spreading under the bark. Sooty Canker is one possibilty, black powdery fingus spreading under the bark. Have an arborist look at it. May be able to remove infect branches, treat with fungicide and save the tree if it has not progressed too far

Water until established and then cut the water back.  Bermuda needs water, but not as much as some of the other types of grass.  Keep it cut short

sounds like too much water.  Pine straw has acidity in it and helps transfer the nutrients properly to acid loving plants.  Fertilizer could also be needed.  Plant nutrient deficiencies vary and sometimes the necrosis in the leaves can identify the issue or which nutrient is lacking... 

Gardenias, I love Gardenias!  Have you tried a fertilizer for acid loving bushes?  You can go to a nursery or even The Home Depot or Lowe's and explain what's going on, and then they can recommend what you should do for them.