How to learn Japanese Grammar direction?

There’s a few things I just don’t seem to be certain about when reading from context.

Examples.

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1.

今日も今日で一人でゲームを始める。

　メンテもあけバージョンアップが終わる。

　一秒も遅れまいとメンテ明けと同時にゲームにインする。

What is 今日も今日で adding here?

What is 遅れまいと adding here, precisely? I understand 遅れmeans late, but what is まいと doing here? I can’t find anything related to it anywhere 😮

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2.

「お帰りなさいませ、ユナ様。バージョンアップ情報はお聞きになられますか」

This part, “お聞きになられますか”, I understand what it means, only from context that if you’d want to be told about the updates, but what is 聞きになる mean, more specifically? :d.

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3.

プレイ時間なら、誰にも負けない。

伊達に引きこもりはしていない。

伊達 I completely can’t understand what this is adding to the sentence, it is somehow translated into acting as hikikomori, or something like that.

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That was it :D.

I don’t know if it’s okay to ask long questions like this, badly formatted and stuff; Please let me know if I should be asking this in a different manner, or if I shouldn’t be asking here at all.

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All the extracts here are from Kuma Kuma Kuma Bear Chapter 1 :D, here’s the link.

[Chapter 1 Kuma Kuma Kuma Bear](https://ncode.syosetu.com/n4185ci/5/)