So vill usually needs to take on the infinitive form of another verb to mean something?
using the verb att bo:
I want to live in Sweden. = Jag vill bo i Sverige. (note: it may be på Sverige)
or using the verb att tala:
I want to speak Swedish. = Jag vill tala svenska.
Do I have all this right?
"Vill ha" means 'want to have'. For example, 'Jag vill ha en kopp vatten,' (I want a cup of water) because 'en kopp vatten' is a thing. While 'vill' just means 'want', you use it when you don't want to have/own something. For example, 'Jag vill gå till sjön' (I want to go to the lake). You can't physically own going to the lake, so you only use 'vill'. If you were to say 'Om du vill ha', that would mean 'If you want to have', and that doesn't have an object so the sentence isn't proper.
The nuance between 'vill' and 'vill ha' is one often looked over in other languages, but the amazing logic of the Swedish language cannot let that be ignored.
for the verb "vill" I think it can be helpful to think of it as being kind of like "wish" rather than "want" when making sentences (but still translate it as "want"). The reason being you can't say "Jag vill hunder" any more than you can say "I wish dogs", you have to have a verb after it--but you can say "If you wish", just like the translation here is "Om du vill".
Question: to what extent are om and när interchangeable? I know när means when and om means if, but if, for example, you were to say: "If/when water is a hundred degrees, it boils", would you use om or när? In English it isn't always clear cut. Is it the same in Swedish? Thanks in advance :)
I think it sounds strange. If by "in a day" you mean "tomorrow" than Swedish would usually prefer tomorrow. But you could absolutely say "we are doing it in two days" as "vi gör det om två dagar".
On the other hand, if you mean "in a day" as in "it will take one day", then you use a different preposition "på":
"Vi är snabba. Vi gör det på en dag." = "We are fast. We're doing it in a day."