There are habits that have been created in the practice. This will not do!

It's like taking the same road over and over again and trying to arrive at a different destination.

Be vigilant to all the aspects of what is happening in the practice: the sense doors, the mind and the speech.

Speech has nothing to do with the mind, just as emotions, feelings and sensations. Speech arises in the same way. Pay close attention to speech triggers -- most of the time it's the habitual response. Sometimes it's the remnants of scaffolding, like the phrases of loving-kindness, or bodhicitta.

Thoughts and speech aspects are different, but how exactly?

Heart-mind is something completely different.