JaVelin:

A repository is an online place where many libraries and applications are stored in packages called "debs" because the files end in ".deb". When you install an application from a repository, Application Manager ensures that all the needed packages are also installed.

Red pill mode, or R&D mode, is a special setting that is not supposed to be used by end users (only developers), but, in this case (and some others) it is necessary due to poor design.

Root mode is necessary to do administrative tasks on your tablet; I like the sudser way the best, personally, but you can choose your favourite.

In your second post, you link to the instructions that my instructions are based on. If the package wasn't broken, those instructions would work.