Thanks for the replies!
Pre-rendering sounds at least better than doing it all by hand, but still it's to limiting for what I had in mind. Adding new animations (and I'm sure over time I'll add lots of them) would be rather messy, and to be true: 8 directions sounded okay when I still wanted to do everything by hand, but the possibility of infinitely various directions sounds even better...
(Not to mention that I'm mainly writing this game to polish my programming skills, so a complex coded solution is always preferable to simple non java solutions )
Still, since I already have to lern Blender for a 3D solution, if all fails I can still use pre-rendering, so thanks again for the suggestion!