Thanks for the tips. I got it working with the original settings. The HDMI monitor I was testing it on was my TV, because my PC monitor is VGA only. On the TV, I was plugged into HDMI ext 3, but I noticed when I plugged it into HDMI ext 1 it showed the desktop, so at least it's booting to desktop. However this method is a bit hit and miss. If I was running it on a standard HDMI monitor for PCs, it would probably work much better.
Overall the performance was better than I expected, especially since it was running from an SD card and not installed on the device's internal storage, which I suppose would be faster. Video playback was a bit choppy, but then again, I would use this for more code like tasks, perhaps. Also getting a monitor with a lower resolution might also help.