I did a bit more research....
1. lpcscrypt_CMSIS just hangs. After 15 minutes and half a screen of dots I gave up. The script uses an undocumented 'print' parameter for lpcscrypt which seems to want to write to a USB serial port which is not there (may work fine under the imho obsolete windows operating system). The VID/PID of the LPCLink2 changes to 1fc9:0083 which isn't even included in the udev rules. Adding it did not make any difference.
2. I tried your 'redlinkserv -commandline' which was the key to the solution (see below). I got the error message version "GLIBC_2.15 not found". So it seems the whole software is compiled with a newer shared library than included in our operating system distribution. I really like to know what was included in 2.15 that was required for the software. Unfortunately software developers assume that everybody always has the latest and greatest version of all the software they are using available.
Of course all of this is hidden by the "IDE" (Integrated Deception Environment). I know why I never liked them...
SOLUTION: LPCXpresso DOES NOT RUN under RHEL6 / CentOS6. We will now look into SGS Thompson (ST) ARM CPUs for our designs now.
@Fall Guy: Thank you very much for your help!