As far as I know, both "volk (German)" and "folk (English)" indicates "people." Then despite the different regions, do these words somehow related, perhaps?

What is the nuance of "see in 〇〇"? Is it an expression?💦

Yes, this is an expression. "See in something" means that you notice the potential, quality, or beauty in a person or thing when others don't see it. You are recognizing a quality about a person that others cannot see. Ex: I can see the fighting spirit in that child. Ex: We can see the determination in you. We know you want to succeed. Ex: Determination and strength are the qualities we see in him.

Why is it two? is it not too?

Very good question. As you probably know, 'too' refers to an excessive amount. However, in this context, the woman mentioned that she'll get her 'out in a jiffy'. But later on, the boy said the glue sticks forever, so the women revised her statement to 'two jiffies', indicating that it instead of "a jiffy" (one jiffy) it will take her "two jiffies" (considerable more amount of time).

What does "bluetooth" mean?

"Bluetooth" is the official noun for a specific wireless connection, where you connect devices within a short range. Apparently, the term "Bluetooth" comes from a King called "Harald Bluetooth", who united Denmark and Norway- the same way a "Bluetooth" connection "unites" ​devices and connections. Ex: I often forget my earphones are connected to my phone via Bluetooth. So, sometimes I wander too far away from my phone, and the music stops. Ex: John, you can send the photos via Bluetooth!

Does the phrase "that's unusual" implies a negative connotation?

Here it does imply a negative connotation! Since it can be considered a negative thing to go against social norms and expectations. But it's not always negative. If something's unusual, it can also be something worth noting or something unexpected. Either in a good, bad, or neutral way. Ex: The changes they made to the company were unusual. I don't think they should have implemented them. Ex: A: My friend has been acting unusual lately. B: A good unusual or a bad unusual?

What's "Qi?"

"Qi" refers to a universal charging standard. It's wireless charging; without cords or plugs. "Qi" is used by many major cellphone companies. Ex: Is your phone Qi charged? Ex: I prefer using Qi-compatible phones, then I don't have to worry about cables.