Wow, thank you for the full run down. This is super helpful and I finally could see the two issues I was having that were making things extra hard (the formality issue and conflating だand です).
The full explanation, especially regarding subordinate clauses, even nipped another issue in the bud, too. I actually am starting to get it! やったー！ (๑˃̵ᴗ˂̵)و ﾖｼ!
Thanks so very much 
I’ve just tried to answer the following with でも :
秋 だけど 、暖かいです。
As far as I can tell, that would work in this sentence, so how is the best way to tell which is the right answer? Is でも more polite than だけど?
Thanks,
Cris
でも comes at the beginning of a sentence, while けど comes at the end of the first clause in a sentence. So in this case you can’t use でも. If you wanted a similar example using でも you’d have to say something like:
秋です。でも、暖かいです。
Ah, I see. Thanks very much 
I am confused as to what it means when けど is at the end of a sentence. For example, I am currently reading a Manga in which a character is introducing himself with “[name]だけど”.
What would the meaning of けど be in this sentence?
Can you provide the previous and following sentence to add a bit more context?
Without context, I cannot tell much, but one possible context is when you pick up the phone and ask why someone is calling you, like this:
田中だけど、（何か(用が)ありますか）？
It’s Tanaka, (do you need something)?
So the dialogue in question comes from the beginning of the Manga “聲の形”, where 2 people (a boy and a girl) meet each other. When the girl recognizes the boy, she runs away, the boy follows her and screams “小6ン時の石田だけど”.
It is later revealed that the boy used to bully the girl heavily 6 years prior
I’ve just bumped into this very same problem!
Do you need to add a だ before けど after all て-form verbs, or just 初めて?
Or is only 初めて possible here?
Are all て-form verbs considered to be nouns?
Is this worth mentioning in the grammar explanation?
Sorry, so many questions! Hope someone can help! Thank you!
I also encountered some instances in which けど with the meaning of “but” doesn’t quite suit.
In this video the other uses of けど made much more sense. けど Is Not Always But
Quick Summary:
けど as a particle marks the situation (A) and transferring to the main point of the sentence (B).
Example:
皆さん、明日田中さんの誕生日会があるんです(A)けど、行きますか(B)？
→ The situation is that tomorrow is Tanakas birthday (Situation)[けど], do you want to go there (Main Point).
Effect: Before make a decision, here is the situation we are talking about.
Another Example:
さっき田中さんにメロンもらったんだけど、食べる？
→ Tanaka gave me a melon just now (A → Situation)[けど], do you want to eat it? (B → Main Point)
I think that also this concept applies pretty well to the translation of “but” and helped me a lot understanding these occurrences in the examples above or if someone picks up the phone and says “[Name], だけど” like stated in the posts above.
田中だけど(A → Situation)、（何か(用が)ありますか(B → Main Point)）？
It’s Tanaka, (do you need something)?
→ establishes shared context to the caller and receiver of a call
Just wanted to share, because i found it incredible useful for me 