TopoftheAbyss said:
Since it makes me less heavy, does it also make Astral projection easier?
Yes, just like working on your 4th chakras does, as well.
TopoftheAbyss said:
Does it make me less lazy or makes it easier for me to meditate? In my current state it is impossible to stay focused during breath exercises or any other type of meditation.
That depends on what causes you that trouble in the first place. Concentration issues can also come from the air element. If you have those issues due to heavyness and/or earthiness, then yes air will help. You can always try it out and see what happens for you.