Peace brother Mubashir.
In my humble opinion, the verb 'tanha' is dependant on context of the sentence. From reading the Arabic, it admits a meaning of refraining, desisting, or keeping one away. Note the usage of 'nahakum' (forbid) and 'intahu' (refrain) in 59:7. Both are formed from the same roots, but the imperfect verb is nuanced differently given context.
A state cannot always stop 'fahisha'. Fahisha is a broad term which compasses many ills, many of which are not always apparent. For example, you cannot impose a law for certain sexual gratifications or disgusting thoughts which all form part of 'Fahisha'. 'Fahisha' is anything which is evil, an excess, an enormity, immoderate, beyond measure or an excessive sin. So something which is gross, or lewd and obscene. This excess can also apply to speech or language (as in uttering foul, evil, lewd or obscene speech). Note how 'fahishatu' is used as excess (in slander / scandal in speech) in 24:19
I hope that helps.
Kind regards ...