Start with the cheapest plan.
If you ever find yourself wishing steam installed a game faster, then upgrade to the next best one. See if that feels like enough.
I pay a bit more for 600mbps, but that’s because I have a home server which runs services for friends and family. It might be streaming media, be syncing nextcloud data, and uploading a snapshot to off-site backup, all at the same time, and it needs to do that without hiccups for anyone accessing it. Even then it’s more than strictly necessary. 350mbps would be VERY fast, and enough.
Along with that comes the ability to install small games basically instantly on my gaming desktop, and big ones in the time it takes me to grab a snack, but even the cheapest speed available would otherwise be more than enough for single-person use.
My siblings and mother live on 10mbps home wifi, and they never even complain.
One side of your deskpad may be grippier than the other. I noticed this with my pad when I flipped it once. The keyboard side seems to have become worn and become rough on a visually unnoticeable level, so my mouse now slides way better one end of the pad than the other.
Also, others have suggested teflon replacements for the skates.
You can also get “universal” adhesive glass mouse skates. Once I tried glass skates on a mouse I never wanted to use anything else.
That said I benefit from this most when I use my mouse for gaming. It might be pointless for average use, but the extremely low friction is very comfortable.