questions about mindfulness and concentration

I have some questions about mindfulness and concentration. 

In the teachings, Thay says we should practice mindfulness in our daily lives and be aware of everything happening at this moment. But we are often doing multiple things simultaneously. For example, if I am washing the dishes, I am also breathing, seeing the splashes, and hearing the sounds of the water. With multiple perceptions and feelings at the same time, which one should we be mindful of?

In one of the mindfulness practices Thay taught us, he says we can practice listening to music with mindfulness. This means being mindful of the music and the melodies while also aware of our breath. But shouldn't we focus on one thing at a time? How can we be mindful of multiple things simultaneously?

When we are concentrated, do we remain mindful and aware of what is happening? For example, if I am listening to a Dharma talk, should I be aware of the words being said or the fact that I am listening to a talk from this Zen master at this place? If I think about all these things, am I still concentrated?

When we are concentrated, we forget about everything else. We don't think about anything else. If I wash the dishes mindfully, I should focus only on washing the dishes and forget about everything else. If that is concentration, then when I am watching a TV show, I forget about everything else and am totally absorbed in the show. What is the difference between that state and being concentrated while washing dishes?

And one more question. Thay says mindfulness is mindfulness of something, but things have names, and names are notions. When there are names, there are illusions. Say if I am practicing mindfulness of my breath, but my breathing is made of non-breathing elements like air, muscles, lungs, and blood. So when I think I am mindful of my breath, what exactly am I mindful of?

Several thoughts along with the contemplation of these questions:

1. we create suffering by projecting happiness.

2. the best reason for practicing doing things in mindfulness is ‘because I like it.’

3. One of the practices for cultivating compassion is to contemplate on your biggest enemy, namely the person who gives you the most hardship in your life, thinking about why he/she does so. what kind of wrong perceptions have triggered the person to harm you?

Upon contemplating this question, it appears to me that the person who gives me the most hardship in my life is myself. It is my ignorance and habitual energy that have contributed to my suffering. 

So self-understanding and compassion arise. I realize that I should not attribute my suffering to someone else, but I should not blend myself neither. it is ignorance and the wrong perceptions in me that is the root of my suffering.