./primecoin-qt: /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.15' not found (required by ./primecoin-qt)
./primecoin-qt: /lib64/libc.so.6: version `GLIBC_2.15' not found (required by ./primecoin-qt)
./primecoin-qt: /lib64/libc.so.6: version `GLIBC_2.14' not found (required by ./primecoin-qt)
Highest version of Glibc avail in stable for Cent/Rhel etc is 2.12
Oh yeah, there are still the glibc and libstdc++ dependencies. Those are quite hard to get rid of. For now your best option is probably to compile it yourself. You can try taking a few pointers from my guide here:
https://bitcointalksearch.org/topic/xpm-primecoin-high-performance-linux-compilation-guide-259022
That only shows how to compile the daemon though. You'll need to install the Qt development packages in addition to compile the Qt client.