Working for GC's can be a great opportunity if there is good communication and expectations are clear.
Payment Schedule
Make sure it is clear. Some can be 30 day, some upon completion.
Sometimes the checks are cut straight from the bank on a schedule, make sure you know when that is.
Lein Wavers
Most of them are printed on the back of the check. Some of the GC's I work for cut the check from their account and have a simple release of lein form. You might check your states requirements. My state has the forms on the Licensing site.
When you get your paint, have store set separate job accounts for each builder/project.
Make sure you specify how much touch up time and the charges for trade damage. You can backcharge other trades.
You may want to include something about availability of water, power, dumpster and portapotty. I have never had a problem with that though.
Since you have done NC, you know the procedure is different than redos. To make it work you have to be efficient and flexible working around other trades.
We spray a lot so we make it clear we need the house clear for the time it takes to spray. We actually prefer NC, have been very fortunate to work with some great GC's
Here is a sample contract.