What would the effects of pre-pubescent castration on a human male be?

As a 19yr old male 5ft 6in (167cm) weighing 132 lbs (60kgs) with a soft low pitched voice, I’m regularly mistaken for being a 14yr old teenager and seen by some people as more ‘feminine’ in appearance (curvy body, lack of facial hair); Yet there are distinct facial features that identify me as a male. Even with my relatively ‘unmasculine’ physical stature, my 5ft 9in, 24yr old female cousin with short nappy hair, would still look more like a woman or at the least much more androgynous compared to me. Its obvious that her facial features have are distinctly different from mine.

In regards to transgender individuals who wish to undergo SRS, some prefer going on puberty blockers or anti-androgens until they have reached the age where they can transition to ensure that ‘masculinization’ or ‘feminization’ of the body and face doesn’t occur and make it difficult to pass as the other gender.

My main question is, what if someone like me underwent castration before I began puberty? Diverging into two scenarios:
a) Castration with no sex hormones present into the body permanently. My body would lack testosterone or oestrogen in any amounts.

b) Castration with oestrogen taken permanently.

Are there also any other emotional effects from this? Do sex hormones have much influence on hte development of the brain during adolescence?

Incorrect premise. Although the testes produce most of the bodies testosterone, there is also some produced by the adrenals.

And the adrenals and adipose tissue also produce estrogen in males and females.

Google castrato Castrato - Wikipedia

It would save him a life of trouble and financial expenses.

I recall reading a newspaper interview with one of the last enuchs of the Forbidden City in Beijing. he was teenaged, so it wasn’t clear whether he was past puberty or not when the necessary job description category was selected by his parents. He was allowed to keep the jar with his testicles.

Apparently there were plenty of job openings for eunuchs in the civil service so it was a plum - so to speak - position. More demand than supply. Eunuchs made good civil servants because they could never hope to be emperor and had no wife and family to try to push into positions in the government or to steal money for, no personal household; and lacked a certain amount of male aggressiveness which would create conflict or problems. But … they were not beyond court intrigue anyway.