I try to answer a few of your questions.
Maybe the 2 dates in the records are the day the move was reported and the day when the move occured. But this is not sure.
The last entry 1.8.14 is separated by a bold line, so I think, that is an entry regarding his father.
To your second question. The Infantry Regiment 115 was stationed in Darmstadt. So I think, this is not Landau in Bavaria. This is Landau in Hesse. Today this Landau is a part of Bad Arolsen and not so far from Darmstadt.