Collins is 100% to blame for the second goal, Kitching was in full control of the situation and needed Collins 10 yards further back so he can knock back that simple header to him, as soon as Collins closed the space he needed to make sure the ball went the opposite side of the pitch.
There was no reason for him to come charging out his goal for the first either, Kitching was positioned well and Collins just needed to cover his front post. Grimes has a simple ball to Thomas I think but chose to force it.
Collins time here is done, he costs us goals every time he plays, the defence have no faith in him, not does he have faith in himself. For the sake of his own career he needs to drop down the divisions.