I have run into this problem as well. Infopath is not portable, and all documentation I have found on the web tightly couples Infopath to Sharepoint Forms server/services.
I was not able to find the Microsoft.Office.Infopath.Server assembly to import to Bin, reference in my project and use on the web as needed.
I was not even able to create a Web Part without my dev environment being on a sharepoint server or have a hard link to one. (makes it difficult to control source for dev environments)
If there is any info out there on how to use Infopath as a standalone forms engine, I would like to know as well :)