Another small improvement for PB would be to have a different icon for .pbp files, when there is a lot of .pbi and .pb, finding the .pbp project file can take many precious seconds.
The icon does not need to be too different, let's say it looks something like this:


Notice how quickly it does stand out.

AFAIK Visual studio and other mainstream IDE's do the same, they use a different icon for the main project file.