The Red Boy demon came out at the gate and cried aloud: ‘Who is it bawling here at my door?’

紅孩兒: the 兒 here is a full syllable, ér, because 孩兒 is simply the word for "child" -- not the light unstressed ending that turns other nouns into diminutives. 出得門來 uses 得 in its light linking sound de, joining the verb to where it got to. 吆喝 is to bawl or holler; the demon has come out to find who is making the racket.

The Pilgrim stepped up and said with a smile: ‘Worthy nephew, play me no tricks.

The whole scene turns on this word. 賢姪 means "worthy nephew" -- Wukong greeting a demon he has never met as family, on the strength of an old sworn brotherhood with the boy's father. 弄虛頭 is to put on a false front, to try it on. He is smiling as he says it, which makes it worse.

This morning, beside the mountain path, you hung high in the top of a pine — just such a scrawny, sickly, jaundiced-looking child — and so you gulled my master.

Wukong throws the morning's trick back in the demon's face. Chapter 40 had Red Boy hanging from a pine in the guise of a kidnapped child, and Tripitaka, who never learns, insisted on rescuing him. 傍 is páng, beside. 那般 is "that sort of," 那 pointing rather than asking. The string of adjectives -- 瘦怯怯, scrawny and timid, 黃病, jaundiced -- is Wukong doing an impression of the performance.

I, out of pure goodwill, carried you on my back; and you straightway raised a wind and snatched my master clean away.

我倒好意: 倒 is dào, the "and yet, on the contrary" sound, not the dǎo that means to topple over. 馱著 is carrying on the back, with 著 as zhe showing it going on. Then 弄風兒 -- and here the 兒 is the light diminutive ending, a little puff of wind, in contrast with the full ér two lines above. Same character, two jobs, close enough together to compare.

Now here you are got up in this guise again — do you suppose I would not know you?

認得 is to recognise, and its 得 is dé, the full sound meaning to attain or manage -- recognising is something you succeed at. That puts it with 記得, "remember," rather than with the light de of 出得門來 a moment ago. 豈不 takes bú before the falling tone of 認.

Send out my master at once; do not lose face and forfeit the family bond, lest your honoured father hear of it and blame old Sun for bullying the young from seniority — an unseemly business.’

The threat, dressed as concern for the family reputation. Send my master out, do not lose face over it, and think what your father would say. 以長欺幼 is bullying the young from the strength of seniority, with 長 as zhǎn, elder. 令尊 is the courteous way to say "your father," and the father in question is 牛魔王, the Bull Demon King. 不象模樣 means unseemly, not the proper look of a thing.