Is it forbidden not to carry out the mother's will to make banners that say "Remember Allah" or booklets titled "Supplication for the Deceased" if they are replaced with other ongoing charities? And is it a sin to supplicate against oneself for self-punishment instead of for the deceased mother while angels are present?

If you are unable to fulfill your mother's aspiration or execute her will, there is no sin upon you. Donating water is among the best forms of charity. If your mother desired to distribute a book but did not explicitly bequeath it, and you believe that the Qur'an is better, there is no harm in purchasing Qur'ans instead. However, if she specifically bequeathed the distribution of a certain book from her wealth, her will must be executed, unless the book contains content that is impermissible to publish. This is unless changing the condition of the endower to what is more beneficial is permissible. If she did not leave money for the bequest, then you may deviate to what is better. It is not permissible to supplicate for torment upon oneself; rather, one must seek forgiveness for the mother and supplicate for her mercy and elevation of ranks.