Why does it say "Pe'amim Rabos (feminine)"?
Ibn Ezra: Every Pa'am in Tanach is feminine, except for "Ach ha'Pa'am ha'Zeh" of Shimshon (Shoftim 16:28).
Why does it say "Yada Libecha"?
Rid: This means that you know.
Why is "Atah" written Chaser (without a Hei)?
R. Avigdor: This hints to Shim'i ben Gera's curse of David "v'Hu Kilelani Kelalah Nimretzes" (Melachim I, 2:8; NiMReTZeS hints to five charges. He is No'ef (an adulterer), Mo'avi (forbidden to marry a Bas Yisrael, for he descends from Rus the Mo'avis), Rotze'ach (he caused Uriyah's death), TZorer (one who causes pain), and To'evah (abomination) (Shocher Tov 3:3). Also David cursed Yo'av with five matters - Zav, Metzora, need of a walking stick, dying via the sword and lacking bread (Shmuel II, 3:29). Similarly Shim'i cursed David in five ways 1 - he said "Tzei Ish ha'Damim" (ibid. 16:7).
Perhaps the five are "u'Mekalel" (we do not say that it is the Klal, and what is written afterwards merely details his curse), "Tzei
What is the relevance that also you cursed others?
Ibn Ezra: Also you cursed others with your mouth or in your thoughts - therefore, do not be concerned for those who disgrace and curse you.
Rashbam: Also you disgraced others, and did not want that they will answer you. So you should conduct yourself like a Cheresh.
Rid: It is a universal custom to curse one another, and [the recipient] bears his colleague's [curse, without answering].
Seforno: Also you cursed amidst enticement of the senses, like your slave did. You recognize that it is not proper to get angry over this.
Metzudas David: Since you know that you did so many times, you should not be upset that they curse you.
