Is it possible to delete the apps in the bottom row or add new ones?
Customisations are not possible currently. Haptique will fetch apps from the Android TV and fixed set of apps are added here. If any app you want is not visible here you can tell us.
In future we can offer a custom view which is user customisable.
I suggest you to post under feature request
I reported a bug here. I hope someone will take care of it.