"youse" as a plural second person pronoun

From an Irish perspective youse sounds totally fine:

The word ye, yis or yous, otherwise archaic, is still used in place of "you" for the second-person plural. Ye'r, Yisser or Yousser are the possessive forms, e.g. "Where are yous going?" https://en.m.wikipedia.org/wiki/Hiberno-English

And from Terence Patrick Dolan's Dictionary of Hiberno-English

YOUS, also YIZ, plural of 'you.' In [the] Irish [language] there is both a singular and a plural second person pronoun, as there used to be in English, with 'thou' as the singular and 'ye' as the plural. The form 'you' was originally the accusative and dative plural of 'ye.' From the 14th century it became customary to use the plural form, 'you,'in addressing superiors in place of 'thee' and 'thou'; from the 15th century, 'you' began to be used in place of 'ye.' From the time large numbers of Irish people became exposed to English, in the late 16th century and onwards, the 'you' form was therefore the normal form of address to a single person. As regards the verbal forms, there is evidence that in the 17th and 18th centuries some people tried to distinguish between singular and plural by making changes to the verb: we thus find 'you is' and 'you are'; but this useful device was abandoned in the interests of so-called purity of the language. Confronted with this bewildering volatility in the use and formation of the second person pronoun, it would appear that Irish speakers of English decided to distinguish singular from plural by attaching the plural signal 's' to the singular 'you', on the analogy of regular pluralisations such as 'cow' - 'cows'. 'Yous all better be back here on the dot of six o'clock or we're leaving without ye.' Joyce, 'A Mother' (Dubliners, 160): 'He said "yous" so softly that it passed unnoticed'; Doyle, The Van, 20: 'Did yis have your dinners at half-time or somethin?'

Prescriptivism at its finest. Simply because a word does not have a position in the standard dialect does not mean it is not a word. Regardless, it is clearly from 'you' (the second person pronoun) and the plural 's'. It fills a niche Standard English lacks: differentiation of singular and plural in the second person.