The US does not care much about Thai issues such as lèse majesté laws, detainees dying suspiciously or even the lack of elections. The US does care very much about the Trans-Pacific Partnership trade deal, and will use the other issues to entice (or blackmail) Thailand into signing it.
After that, the issues would probably disappear into the ether, conveniently ignored and forgotten – poof, like magic!
That is, of course, a familiar pattern (think Viktor Bout).
Ironically, the TPP probably will not be approved by the US Congress without major renegotiations, and not until 2017, according to the Republican leadership. Republicans control the US Congress until then, and powerful Democrat congressmen also oppose the TPP, so it seems doomed.
Signing the TPP might yield some political gains for Thais and for President Obama, but it seems otherwise irrelevant or meaningless in its present form. It could be signed today and rejected later, during renegotiations.
Guy Baker