Is it a requirement to use the release candidate? I tried many times this evening using the current iso and couldn't get it to ignore my sda1. Also is there a command line install option to use vesa? No in the wiki, by an option on install
AFAIR I installed more than one SME9 via usb using unetbooting on windows and copying iso file onto USB stick..
the only issue I had (and IIRC there's a bug related) is that grub is installed on the USB key itself and so you need to boot with the USB key in, installa grub on your hd and reboot again.
in any case, you aren't giving us any detail about your issue, so it's hard to help you