There are different translation methods, including the one that does not require deconstruction, rather, cultural equivalence. How to justify - depends on your standpoint in the process of comparison, your purpose.
To an extent, yes. Translation, after all is a process of ’transfer of meaning‘ and it often requires shifts from the SL to TL, i.e. from a lexicon to a phrase or sentence or an additional morphological information. To enable these shifts (whether to achieve equivalence or to conextualize or toincorporate stylistics) , deconstruction is needed. you might want to read Derrida, and Pound (in Venuti) & also Davis
Deconstruction is a common practice in translation that creates new terms necessary for analysis and interpretation, to mark cultural differences and interplay of concepts in opposition. So when translation comes up with new words, unfaithful though they are to the source text, it can readily find an ally and a backer in deconstruction.
Translation, is a two-way process of transferring of a bundle meanings including cultural based ones and it requires deconstructing the SL meanings to convert them to TL.