To me putting it first feels funny. Euro 100, instead of 100 euros. While writing it you need to remember to put the symbol before writing the amount. Funny thing

I dont know why that annoys me. It does annoy me but it shouldn't because at least it has a logic to it.

£2 Is spoken "two pounds" not "pound two"

Listen do you say Dollars 300 ($300) or do you say 300 Dollars (300$)?

I rest my case lol

I feel like that would have come up at some point during my two years of thermodynamics classes where we were constantly using ∆T. just did a search for "C°" in quotes, and for delta T; first one returned nothing, second showed a bunch of sources where the units of ∆T were °C. any idea where you might have heard this?

I'm pretty sure you've made this up. °C is the unit regardless

How would you "say" this, "Five Celcius degrees more..."?

I reject your reality and substitute my own.

I've always seen Kelvin used to describe differences in temperature, since Kelvin has a real zero point and the steps are the same as Celsius. Or people just use °C because they don't know or care that it's technically wrong.