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! 

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

Besides the painting suggested by Chad of Lonestar Painting which can truly makeover the appearance of a home, I suggest that the trees and shrubs be professionally trimmed and thinned out.  Application of weed control and fertilization of the lawn will provide a healthy and attractive canvas to your yard that can be supplemented with a dose of spring color annuals

Tree removal is not normally a part of what we do at Blackdog Builders, but I thought I would look up some information for you and offer some advise. First of all, if the tree is too close to your house where the branches are reaching over your roof, you may need to replace your roof more often due to debris or branches. This is a bigger problem of course with pine and it's sap, but an oak tree will produce acorns and will also shed leaves every fall. This may damage your roof, and if you have a gutter system, it will need to be regularly cleaned. 

After some research, it seems that oak is one of the more expensive species of trees to remove because it is a hardwood and usually grows very tall. The following is provided by treeremoval.com:

"Oak is one of the strongest, toughest woods out there. For that reason, tree removal services often charge a premium to tackle them. Oak trees are also very tall. The average height of a healthy oak tree is 60 feet. You can refer to the price guide above to see that you will pay between $200 and $1,000 to have an oak tree removed. Due to the fact that oak is such a solid, thick wood, your total price will probably fall on the higher end of the scale. Make sure you have a really good reason to have it removed before spending that kind of money!"

Hi John, where are you located? It sounds like an expensive endevor to go artificial. How large is the grass area that we are talking about. This could help with the cost estimation.

A very quick and cost effective way to upgrade your homes exterior is a cleaning and color change. Pressure wash to clean it up and paint the shutters and front door.  They can remain the same color or pick a fresh new color.  You can also take any old fixtures that have faded over time and paint the metal with a fresh satin or gloss paint.  Same with metal railings or metal awnings. Possibly a one day job with big results. 

We just had sod installed at the office here at Crown Builders in Charlotte, NC.  The landscaper told me to water each day for 15 minutes the first 10 days.  From 10-21 days after install water every other day.  After 3 weeks and beyond cut the lawn as needed.  It should be fairly well rooted and can take normal wear and tear. Give it 1" of water each week.  Apply balanced turf fertilizer 6 weeks after install.

We agree with Geoff's suggestion and would also recommend speaking with a local landscape architect. They not only handle plant specifications, but also deal with drainage and irrigation. They will be able to assist you or point you in the right direction to solve your issue.  

A landcaping contractor might help. Depending on your location, you may be able to find someone here: http://www.guildquality.com/find/Landscaping-and-hardscaping/North-America

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... 

Be certain that this is something you plan to use for years and years as the ROI on homeowner-specific improvements are not very high.  Budget for the concrete work involved is usually around $15-20K alone, not including the poles and painting.  If you plan to sell your home in less than 10 years or would need the court for less than 10 years, don't do it.  A new upgraded entry way, minor kitchen update, interior room/living space addition or new Hardie Board siding will give you a much better return on investment.

What is the water source? It looks like it is coming from a drain pipe behind a shrub? I would recommend relocating that to dump to a different location. No matter what type of edging you install on the bed with the mulch, a massive amount of water from that down pipe will cause some overflow and mess. Maybe you can incorporate a stone trail where the water flows, if you can't relocate the down pipe. Ideally, I'd want to see the drain pipe go under the side walk, and out by the grass, or if its by a garage, down the driveway.

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

Awesome answer.  Goat are machines and they do have rental goats.  You will need to keep them penned up where you need them though or they will clear you out.