You could try installing the ntfs-3g package and then seeing if you can get around the issue without knowing what is wrong. Other than that...I guess any extra information you can provide would be nice.
Installing arch is pretty simple. Boot installation cd -> partition what you want -> pacstrap base -> arch-chroot -> setup hostname/timezone/normal user/etc -> reboot.
i also tried to install arch on virtualbox a while back, i couldnt get it to work.
Here is a screenshot log of me installing Archlinux in a VM. Around about an hour with screenshotting and watching youtube videos. It's simple and quick enough that I don't mind doing it while derping with other stuff.
http://imgur.com/a/wQxZb
Also, after reading the thread you posted I really agree with this guy:
https://bbs.archlinux.org/viewtopic.php?pid=1367809#p1367809
It's not that they aren't willing to help, but it's as if you didn't know what UUID was and didn't make the effort to really understand what you were doing.
- edit -
well i installed it on a usb FROM virtualbox
After thinking about it for a little bit. You probably didn't set your syslinux.cfg correctly.
<Insert I wish you gave more information of the situation here because I don't know if you actually get to syslinux or not> You can check if it's a syslinux config problem by manually highlighting the entry, pressing tab to edit the arguments, and check the "root=" location to verify that it's pointing to the partition/device you are intending it to. If it isn't, set it to the correct device and boot into your arch install.
After, you should open /boot/syslinux/syslinux.cfg in a text editor and change the entry in question to "APPEND root=<UUID of USB>"...If I'm understanding this correctly anyways and you are intending to use that USB as a persistent mobile archlinux install.