USB-C is just the connector and can have a lot of different implementations (USB 2.0, USB 3.0, Thunderbolt 3, etc.).
So its up to the manufacturer what they implement in there hardware.
Looks like your laptop doesn't support video out over USB-C.
But according to the msi website your laptop has mini Display Port and HDMI so you could connect two monitors over these connectors.
Im using two 1080Ti in SLI myself and looking at hardware usage while gaming, the second card is mostly just for the looks in my system. I got a pretty good deal on my cards too and have no interest in upgrading in the near future.
As Statik says: dont waste money on a 2080ti and keep both cards if you dont need the money or have problems playing your games.
If you want to upgrade wait for 3000 series.
I have one 360 rad (30mm), one 360 rad (60mm) and one 560mm rad (60mm) to cool a 8700k and two 1080ti's with very slow running fans.
My water temp never went over 38°C at 23°C ambient (max load on everything).
I could also cool my hardware with both 360 rads at high fan speed but went the silent route. (My 2bay NAS with a 92mm fan on the other side of the room is louder than my PC right next to me)
So if you want a silent computer go with as many radiators as possible.
And a watercooled PSU is not really necessary.
According to the MSI website, your motherboard supports 7.1-Channel High Definition Audio and Supports S/PDIF output.
https://www.msi.com/Motherboard/MPG-Z390-GAMING-PRO-CARBON/Specification
The case is big enough but you should add some fans to it. If you place the AiO at the top, remove the solid panel and use the dust filter only. Add a second 140mm fan at the front.
no issue
Maybe you should look for another board with sli support. otherwise the second card is just a waste of money.
Game ready drivers and studio drivers are nearly the same.
Studio drivers are an older version of the nvidia drivers with more testing for best reliability for content creators.
game ready drivers gets updates more frequently for best performance in games.
so if you are a gamer just install the game ready drivers.