XPages code is a mess, it does not handle situation, where browserfeatures are missing and it is not accessible by default. This might be acceptable for internal websites, where you can control the browser and users, but it is not for customer facing websites. This should be fixed.
It's als not accessible (try tabbing to the XPages example: you don't reach all links!), which im my opinion is a requirement nowadays in public websites. Xpages sites should comply to this per default.
Another thing is, that the code is a bloated and should be cleaner and smaller, so that it will load faster (and cheaper: less bandwidth used).