@WTU to my knowledge, and @jgontheir correct me if I'm wrong, MPI is only going to speed up the integral direct Hartree-Fock part of your computations. In my experience, you're better off with threaded density fitting unless your system is huge.
As for boost mpi not being built, that is a bug. Unfortunately Boost made the build process arduous, so tracking down why it did not build, in your case, is going to be tricky (I routinely build with Intel, so I don't think that it is simply that you used Intel compilers). Inside the build directory there should be a boost subdirectory, inside that directory should be a boost_1_57_0 directory, inside that directory should be log files. In my experience, the error usually appears in the normal log file, not the error log file. Making matters worse, in my experience CMake (?) cleans up the boost build, if it thinks it is successful, and in the process destroys these logs.
If you are set on trying to compile with MPI another option that you may want to explore is manually compiling your own version of Boost, with MPI. You can then tell the Psi4 setup script to use that version.