Incomplete Syncing

So this is an enduring issue since Apple required us to sync via Finder.

Few months ago, music was the only thing that would sync correctly with my phone, where as pictures would go from my phone to computer but not vice versa. Now, pictures are the ones that'd sync to my phone, whereas music (including updated playlist) would not follow.

I also noticed that songs I purchased from iTune store recently would no be on my computer, instead they'd be stored in the cloud until I create a playlist, so I manually created lists for new songs and tried to sync again. Nothing. What's even more odd now is that my photos stop syncing afterwards, retains the most recent addition but refuses to take in more pictures.

Some info to consider:

1) I sync with cable.

2) I don't use iCloud for music/photos.

3) I still have 15GB space on the phone.

Does anyone else have this (long-term) problem?