updating

Check here.

You may, or may not get steam trade/market ban for 7 days, depending on where your steam is installed and the method you use to install.
If you have multiple partitions, and Steam isn't on partition where OS is installed, it doesn't matter which method of installation you use, you should be safe. Just launch steam from the folder, over the steam.exe.
If they're in the same partition, you'll need to upgrade keeping user files, instead of formatting.

steam worked fine for me after the upgrade. no issues at all.

I did the upgrade, no issues here.

as long as you don't replace files inside the steam folder, it shouldn't reset your steamguard status.