I suppose the phrase "wakey wakey" is an informal expression however, is it a more kid-friendly expression? Would it be awkward to use it for grown-ups?

Does "bigger than [one's] feet" an idiom?

It's not an idiom, but it is a bit of a joke! So, here, a "Hobbit" is speaking, and in The Lord of The Rings, "Hobbits" are known to have really big feet. So metaphorically, he's saying their hearts are bigger than their feet, to mean that they're really kind-hearted and well-intended. It's put emphasis on how kind they are - to what extent, which is a lot in this case. Ex: Her heart's bigger than an airplane, that's how kind she is. Ex: It's like his heart is bigger than anything.

What does it mean to "be high"?

"High" has a couple of different meanings. In this video, "be high" means to be extremely excited or euphoric. She is telling a story about a little girl being so excited to see her after the show. Most of the time, "being high" is associated with illegal drug usage. However, it is also occasionally used and associated with something that makes you feel excited and positive about a person, thing, or event. Here are a few examples of "high" being used in a similar context as it is used in this video. Ex: Skydiving gives me such a high. I can't wait to get back in the air! Ex: She is very high on life. She is very adventurous and always making the most of every situation. Ex: Runners often talk about the high they get after their strenuous workouts.

Is "take" a verb usually used with sauna?

Yes! Actually, it's common with and without it. To "take a sauna" means to have a session in a sauna. It's similar to "take a shower." But it can just be used as a noun form and as the base form "sauna." I've heard it more commonly as the noun form! Ex: We went to the sauna this afternoon. Ex: I'm going to take a sauna later. Ex: Does she want to sauna?

What is 'em?

" 'em" is short for "them".

What's "precedent busting" mean? Is this proper to say in a formal speech?

Here, "precedent-busting" is a compound adjective used to describe the "appointments!" It means these new appointments are breaking the norm and changing what was expected within the Cabinet roles. I wouldn't say it's common to join these words, but within this specific context, it works well! Ex: Having three managers at the store is a precedent-busting occurrence. We used to have only one. Ex: The town elected its first female mayor! I'd say that's precedent-busting.