Although you have already selected an answer i am adding another one.
The reasons are two:
All your questions are answered in Manu Smriti itself and
The punishment for verbal abuse is also explicitly given in it which is missing from the selected answer.
Hindu Shastras describe 3 kinds of sins:
- those done by mind(thought)
- those done by speech and
- those done by action.
From chapter 16 of Essence of Skanda Purana :
Adharmas or Acts of Sin are mainly of three categories: ‘Sthuula’ (in Gross Form), ‘Sukshma’ (Small in content) and ‘Athyantha Sukshma’ (Minute). These sins are performed by Mind (Manas), Tongue (Vani) or Karma (Action). The Manasik type is four-fold: Thinking of other’s women, wealth, material loss and difficulties. ‘Vachik Paap karma’ (Sinful Utterances) like lies, unpalatable sayings, blaming others and using provocative language
Manu Smriti also talks about these 3 kinds of sins.The verbal sins are described as follows:
12.6. Abusing (others, speaking) untruth, detracting from the merits of all men, and talking idly, shall be the four kinds of (evil) verbal
And the following shloka ,found in the same chapter, gives the punishment as well for verbally committed sins:
12.9. In consequence of (many) sinful acts committed with his body, a man becomes (in the next birth) something inanimate, in consequence (of sins) committed by speech, a bird, or a beast, and in consequence of mental (sins he is re-born in) a low caste
And also can we use cursing for condemning bad/evil things?
Yes, (as per the Manu Smriti) one should always speak the truth and condemn the bad evil things however harsh it might sound.The following is a relevant verse:
4.138. Let him say what is true, let him say what is pleasing, let him utter no disagreeable truth, and let him utter no agreeable falsehood; that is the eternal law.