Shinji in the manga is a bit snarky at times, which I think gives a bit more to his character. Good stuff.
Not much is actually mentioned about Shinji's life with his uncle, but the fact that he wasn't particularly welcome is clearly visible. The ending monologue demonstrates pretty much what Shinji lacks: A willingness to ask people for help regarding his feelings. Clearly he would rather stay within his shell rather than interact, which is ultimately detrimental for his own cause anw. Whether that's due to a lack of understanding from the people around him or otherwise is up for debate.