Kay, let me rephrase that: It doesn't feel cheaply coded, just cheaply made and cheaply designed.
The UI lacks tooltips and proper explainations, it lacks coherence and doesn't display everything you want. The whole thing lacks tooltips.
If it took effort to code then that effort was wasted on an undercooked concept and at the very best slightly below average graphics work.
every mod in minecraft uses books to explain mod details, you can create that book by 4 limonite around a vanilla book and all the skill information is there.
I don't think it is possible to add mouse over tool tips to the skills GUI. If it is possible that would be amazing to see though.