I'd be interested in seeing research comparing the effectiveness of this approach to spaced repetition in terms of language acquisition. The best I could find was an IEEE paper discussing the subject for English vocabulary acquisition in Chinese universities (http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5677128&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D5677128). 

My gut feeling is that mind maps probably can't compare, in terms of number of terms retained, to space repetition, at least when it comes to enabling recognition. I can see how mind map exercises could be valuable, however, in *speaking*, where it's important to be able to recall the word you need at a moment's notice. In that scenario, having run exercises with mind maps could help you get from a general concept like "feeling" to "bad feeling" to "worried", "anxious", "angry", etc. 

Some people use Heisig's Remembering the Kanji system, but that never appealed to me. I started by using an SRS system. I now use Skritter, which lets me practice writing as well as recognition. Once I had enough characters and words under my belt, I started reading simple articles, and slowly built my way up from there. I have about 1600-1700 characters and a number of their on and kun readings down after a year of daily effort.

頑張って！