In "estoy que ardo" both verbs are conjugated (same tense and mood)
.
2) and 3) use English indicative when they should use Spanish indicative (and when Spanish indicative doesn't apply, a different mood)
Later, there is some hesitation in the way that person is addressed, with
usted followed by the conjugation for
tú.
I don't have any idea what the "luego cuando seguía preguntarle las mismas cosas necesarias" bit might mean.