How big is the stick? assuming 8 gig min
No..there is no live option for the development iso's.. Old School installable operating system
To install to usb you would likely have to have the usb stick formatted for install like a hard drive and install to it like one as well..unetbootin will create a bootable installer on usb not a bootable OS
If you created a dvd and proceeded to install to usb and it did not install the boot loader at the end you could try booting the stick with the dvd: linux root=/dev/sdxx ro (xx is what ever your stick is)
just my take on it..not a good choice for thumb drive linux but an option. It can also be made to work in virtualbox via install, but is best installed to compatible hardware of which there is a vast selection.
knowledge of your experience would be welcome naturally I have not done a direct install to usb but did have the same response installing the bootloader to a second partition rather than the master boot record and booted via dvd no issue.
There are live cd for current standard release you can find it herehttp://vectorlinux.com/downloads#standardLive
persistence is not an option for live usb however it is linux and you are free to make it so if you have what it takes..