Those changes are easy enough to do manually (most info is on the FAQ on the wiki and actually it has more info to make the boot even quieter so there is no text at all or raspberries…)
and to amend my previous statement I guess there is a package for the raspbian version of LXDE (you install it after you’ve installed lxde), its raspberrypi-ui-mods so that’s easy enough to install with it and shouldn’t be a problem.
Rookervik has already created a desktop theme for the default carbon theme, so that isnt any issue.
But I think I’ll leave it under ports for starters just for simplification especially considering the amount of systems retropie already has along with the limitations of a lot of the themes (It also allows people the freedom to create their own themes if they want)
There are a few things that need to be addressed with autostart functions on jessie before I can build a proper module to install it but once those are addressed I’ll add it to the experimental menu of the setup script.