I can give you my thoughts:
Physical training increases your players condition, but I can't see that it helps against fatigue. I tried to rotate a lot playing with Juventus, and with Serie A, the italian cup and CL, thats alot of matches... So my players got very exhausted, and I skipped physical training to see if that helped, but it didn't, their condition went down, and they didn't last long in the matches. So I tried to do the normal physical training every week, then I think they lasted longer, but in the end of the season my midfielders was very tired, it took some weeks to get them on their feet again... I think it's a little unrealistic, because it doesn't happen that often that a teams central midfielder is substituted, it takes a lot for a new player to get into the match in real life (not in fifa
)
Individual training:
If you want to increase a players shooting, just choose shooting, and let it stay that way, it's not enough with just a week or a month. Watch the plyayers bio, there's a bar (was it green?)next to the ability you're training, and when that green bar reaches the top, his shooting abilities increases... note that training shooting affects both shooting accuracy and shooting power.
Well, thats what I know, from playing the and reading this forum, hope it helps, and that you understand my english