With regards to Kenichi getting stronger, in the more recent manga he's sure come along way since the start (though he improves pretty steadily). See the "spoiler" image for Kenichi in his rather cool custom dougi.
Spoiler for cover of vol 20 of the manga:
Please note that the funky glowing stuff is just
FOR EFFECT, not a representation of some "super move" or something.
I hope the anime turns out as well as the manga (which starts kinda slow but develops very nicely).