@felix330 Don’t forget to post the page numbers for the dialog you’re asking about.
I agree with your translation, and I’m also not sure what 親しまれております means here…
I fixed one typo (やんなきゃ, not やんなきや) that might clear up a little bit, and I added the last part of the speech bubble.
星間: I’m wondering if this actually means “interplanetary”, rather than “interstellar” in this context. The only monolingual definition I found was 「星と星との間。」(not particularly helpful). That same dictionary defines 星 as 「恒星・惑星・彗星・衛星などすべての天体の称」, so I’m pretty sure it can refer to a planet too. Hence interplanetary.
うんとこさ: A lot; plenty. This is a と adverb, which means it needs a と afterward to connect it to the verb.
やんなきゃ: This could be a deformed version of やらなきゃ, meaning “have to do”.
始まらねぇ: Deformed version of 始まらない. Apparently it means “It’s no use” according to jisho. This word in the sentence is still throwing me off, but maybe it’s meant to be read separately from the rest of the sentence.
Essentially, the mailman is highlighting the contrast between how they have interplanetary travel, but still do a lot on boats. I’m bad with actually writing out translations, but maybe something like this:
“In these times where interplanetary travel is possible, we have to do a lot on boats. It’s no use… this town.”
I’m not too sure on that last part.
This kind of relates to the next speech bubble where he says 「まったく不便で不便でならねぇ」. It seems like from the context he would be saying it is inconvenient, but then why ならない in the negative? So I feel like I’m still missing something about this.