'so you have grown to care for the boy'
'always'

Doesn't this prove that Snape always cared for Harry?
Snape was more comfortable being a hated person i think. When it is ALL you know. going back to Snape's Hogwarts days and then Death Eater days...

I think he got used to having a certain type of public persona/character.

Imagine - if Snape had favoured Harry - the backlash from Slytherin parents... other Slytherin kids... the Malfoys... SNAPE had NO choice but to treat Harry the way that he did.

Snape always helped Harry when it mattered. for Snape to try to expel Harry, do you honestly think Dumbledore (who had the final say) would have agreed? I'm sure Snape knew that Dumbledore would never expel Harry. I think Snape trying to expel Harry was more about 'keeping up appearances' and acting in a consistent manner, rather than a genuine need to expel HP.

'always'