Just remember that the Bornless is a newer interpretation of the headless rite. Goodwin’s translation of the Rite of the Headless One is the most relevant, The Golden Dawn and Crowley used this to make contact with their HGA. If I recall Goodwin mentions and identifies the Headless One with the Deit...
Dont worry just keep at it ..You will get used to it I have been through the same thing so I know what you are experiencing. I also agree with validus try changing your schedule do them in the morning etc.
The spirits are not neccesarily English It should not have any less Impact. Do it in whatever language you are most comfortable with but as mentioned make sure you retain using the God names correctly. Most of them are phoneticaly spelt out at the bottom of each Ritual or spell...
It is the same as the Golden Dawn's Middle Pillar Ritual. The only change is the word Da'ath to Da'as as far as I can tell. It would do you no harm in doing more research on the Middle Pillar as the NAP system is almost purely Qabbalistic in its nature.