Regarding your question about Krishna recommending the chanting of His Holy Names, probably you have not marked it in your study of the Bhagavad-gita, but in chapter 9, verse 14, Krishna describes how His devotees are always chanting His Names. Lord Caitanya, although He is Krishna Himself, is even more merciful than Krishna in that He has shown to the fallen living entities of the kali yuga how the chanting process can immediately elevate one up to the spiritual atmosphere.
Letter to Harer Nama, 21 December, 1968