My handwriting is awful, too. I am mostly with you on the Note 3 (which I also have), but the handwriting recognition is great on the surface. I also use it just to "click around" when using it in tablet mode on the couch :)
There is another thread that discusses the microSD card dismounting at will. Several posters claim it is the SanDisk cards (especially the 128GB) that do this. I have only used the SanDisk 128 GB card and have the dismount issues. But they are infrequent enough right now that I just live with...