Should've stuck to his guns and walked in the Summer when he wanted to.
Indeed. He was clearly uncertain and dithered about taking the job, was not a good sign.
Lack of quality in squad, been poor attitude within squad (I wouldn't rule out survival completely becuase they always make a late rally) and seems Advocaat has fallen out with some players, seems like didn't get transfer money he needed to rebuild squad, problems at the top.
However even with Advocaat having improved their firepower and midfield, even when they try really hard, Sunderland only seem able to get draws. Very worrying for them but if they get relegated, this has been coming a long long time.