The initial bootloader splash screen of the install cd does say vlocity for your 64-bits PC on 32-bit vector versions. True of Light RC1.4, and I think for RC1.5. That's just some misplaced text, no more; and I think it's being fixed.
There were several retries when building RC1.4, you may have gotten one of the "oops" ones. If the CD booted and the installer started when trying the install to USB, chances are the machine is fine for 7.1. I got confused when looking at the Dell's specs, but I think that one's a no-go until a way is found to put the needed non-pae stuff into the downloaded install iso/extraction. Please say so if I'm wrong about the Dell being non-pae.
As far as installing to USB, there was a very recent fix to the installer to improve USB as an installer medium. Those changes are in the Light RC1.5 and STD RC4.2 iso's. Magic 8-ball says 51% chance that will help when installing to USB, if it has the space.
Light RC1.5 and STD RC4.2 won't be rebuilt -- that is, if other iso's are to be created, the version number will be changed. If a new RC version is very "fresh", say a day old or less, it might be a failed build that hasn't been cleaned up yet.
Oh -- for Light RC1.5, and probably STD RC4.2, I suggest that if you're disabling the boot splash, choose grub for your bootloader. Lilo seems to have problems in this setup if the initrd (containing udev) isn't loaded.