I: Is BU the boy ACH-ING? Is he AH... ILL?
II: Itheann an buachaill arán
Nominative: buachaill buachaillí
Vocative: a bhuachaill a bhuachaillí
Genitive: buachalla buachaillí
Dative: buachaill buachaillí
♫: IS BU HUL MAY
Is bu ach a ill mé
RIGHT SIDED ACCENTS: are equivalent to the SPANISH KEYBOARD
Á É Í Ó Ú
Yes, nouns are either masculine or feminine, and the way initial mutations, cases and adjectives behave changes accordingly. In terms of pronouns, there are two gendered pronouns: sé (he or it, when referring to masculine nouns, or to an unspecified "it") and sí (she or it, when referring to feminine nouns).
When you are a beginner, learning the word with the article doesn't require more effort that learning the word alone. I agree, it's like French or German. Pattern are more obvious in Spanish than in French or German, so this method is the best in my opinion. And you deduce some pattern afterwards, when they exist (not always the case in these languages)
It's not a glitch, it's just the way the voice actor read the script (unlike most other languages on Duolingo, the Irish course doesn't use a text-to-speech engine, all of the spoken Irish sentences on Duolingo are actual recordings). It doesn't sound like an interrogative intonation to me, though she does put some emphasis on mé that wouldn't always be there.