Yes you can install themes (only one at a time though).
To install a theme from the forum, download the zip file to your PC, open your web browser (I don’t recommend using IE9, there have been issues), then type your SMP’s IP address to open the Web UI. Type in your password (the default is “admin”), click on the box next to “I accept” and then click on LOGIN, then click on “Appearance”, then click on “Browse” and navigate to where you saved the “theme.zjp” file, then click on “Open”.
Click on “Submit”, then once the Web UI finishes uploading the theme, on you SMP press “Setup” on your remote, select “Appearance”, then select “User Interface Themes”, select “Theme name” then when prompted select “Apply theme”.
Alternately, you can download a couple of themes by pressing “Setup” on your remote, select “Appearance”, then select “User Interface Themes”, then press the red button on the remote to switch to online content.
Also, as already explained to you in the HUB forum, no you can not get info to display for folders. But if you don’t want all your movies in one big folder I suggest you sort them into Genre folders.
And no, XMBC does not work on the SMP or will it ever. The SMP is firmware based not software based, so you can’t install software on it.