I’m going to do H in a separate post because the first with F & G is getting too long to reliably edit. Also, I’m gonna stop right after this because it’s taking too long. Will probably reply to other things tomorrow. I wanted to finish F in half an hour, but it took me 1.5h to finish even though I already understood the sentence at the start. 
(half-crying, half-laughing) I won’t have time for anything else at this rate…
(Note: I’m typing the pronunciations in the explanation instead of as furigana. I will split the kana kanji-by-kanji)
H
常識的 に 考えて 手遅れ だった から だ
commonsensical [adverb] consider-TE hand-lateness be-past because be
Translation
Thinking about it commonsensically, it’s because it’s too late.
じょう/しき/てき: 常識=common sense/knowledge. 的=an ending that turns a kanji block into an adjective (it has a similar function in Chinese, although its overall function in Chinese is like の’s in Japanese). The result is な-adjective. Adding に turns it into an adverb.
かんがえて: 考える=to think/consider.
て/おくれ: ‘too late’ or ‘the state of being too late’. I think it’s used like an adjective, but grammatically, it’s treated like a noun (so we have to add の after it and so on…) The reason I said ‘hand-lateness’: I’m trying to prove that even native Japanese compound words function with the same logic as kanji compounds. Realise this, and it’ll be easier to see Japanese as a whole, and not just kanji + everything else. And yes, so, if you reach out your hand and it’s late, that means you’re ‘taking action too late’. Logical, right?
…[verb]からだ: This is a way of saying ‘the reason is [verb+the whole sentence that came before it]’ This is the more complete way to respond to the question ‘why?’: 「〜〜〜からです・だ」, instead of stopping at から
EDIT to respond to another post: @Zizka
True, I think everyone interprets it as a sequence, especially because the passé composé used in my example is a tense that means ‘the action is completed’, which is why the adverb is needed. But what I meant was that the words describing the action stay exactly the same, it’s just that you need to add an adverb (i.e. more context) in order to make the meaning clear. The « et » itself doesn’t reveal whether it’s a sequence or not, even though it makes more sense and is more common to interpret it as a sequence if there’s no context. So you have to guess based on context and logic (i.e. can those particular actions even happen at the same time?). See what I mean?
And yes, you can see と as the noun linker, and て as the verb linker. Does it make more sense now?