Mine's a Maxis SIM. Duplicated from my main line to be data-only. Not sure if that makes a difference, but from what other people have said even normal SIMs with data + mobile line should work.

SP7+ is listed as a business device: link

Not available to purchase from the MS authorised store on Lazada. I never checked whether physical stores like Thunder Match will have it, but I have my doubts. Might have to go through a business reseller, which I have no experience in.

If under warranty then very simple. Just create the support ticket online - they will email you the shipping label and arrange pick up time - you pack your device securely and stick the label on and hand it over to the courier - once MS receives it then they will inspect - if no issues with the warranty claim then the next email you'll get from them is them tell you your replacement has been shipped out. Whole process probably 2 weeks max? Not sure how COVID would've affected this timeline.

One of the resellers told me Malaysia will be January 2022 for the Laptop Studio. I assume Pro 8 should either be same time or earlier that than since it's an established product. But who knows with Microsoft.

I have updated my devices to Windows11. Surface Pro X, Asus Zephyrus G14 and Surface Go3 (my Go3 is commercial spec and came with Win10). So far no issues, loving Windows 11. ProX also feels faster.

Surface Laptop Studio is out for pre-order now! One skew each for the i5 and i7 models from Shopee and Gloo. Just locked in my i7!

I have the Dell Thunderbolt Dock and it works good. But it's TB3, so if you absolutely want TB4 then might need to do a bit more digging.

There's no harm. I use the 100W charger for my Surface Laptop Studio and Go 3. Cuts down on bringing around multiple chargers.