Biblioscape does not meet any standard criterion as a portable program because it is obviously still using the registry to keep track of its files. That means that in any computer in which registry changes are blocked, it will possibly fail badly. More importantly, it leaves traces of itself on the client computer. You might consider using the U3 model if you want to do a USB type program. I do not like that model. I prefer portableapps.com's appraoch. However, the SANDISK u3 model would allow you to tie your program to the user/key rather than a computer.
We have a plan to make all
We have a plan to make all settings potable. In Biblioscape Options window, let user chose to save settings in registry or ini file. So if needed, all settings can be saved in ini files and become fully portable.
Consider an XML structure for your options
An XML such as used by Filezilla and other portable programs might be more useful than the old INI.