GW2's installer window has some fancy alpha channel window stuff going on that doesn't always work with all graphics cards. It'll cause GW2 to not start installing, even possibly freeze your computer.
The workaround is to launch Crossover, click the Bottles button in the top-left, select the existing GW2 bottle (or the bottle you want to install the game into), then go over to Control Panels and open Wine Config. Graphics tab, check on Emulate Virtual Desktop, and set the size to something like 1024x768. Then run the GW2 installer against that bottle and the installer will open and display inside a larger window, but not crash or freeze the computer.
After it's finished installing you can go back and uncheck the Emulate Virtual Desktop.