Just a side note from what you have said here i do not think windows is configured properly. If you were to keep it i would be recommending a full fresh install and configuration of windows.
If you are able i would definitely consider returning it and getting something along the lines of what @Scott has suggested (although like you did previously i would recommend the MX-4 thermal compound).
Out of interest do you have Control Center installed and configured?
It's £70 quid what the hell! I haven't been on steam for a couple of months now. I was hoping to get the ff remake when I got back from my work trip but not a chance if they are selling it for that!
It does sound like a pretty good bit of kit. I've said before the main thing i would probably use it for is emulation. Its emulation support looks absolutely insane.
What sort of games are you playing on it? Do you find the majority just work or do you spend ages messing about with them to get...
So my steam deck is due to be available starting next month. For those of you that have had one for a while is it worth while. I am sitting on the fence a bit at the minute. I am away with work and have been absolutely glued to my switch in what little free time I have. It has got me thinking do...
That Intel CPU does run hot. In terms of weather you should be worried or not would depend on more testing. If you want more advice start a new thread and people will help you test your thermals.
P.S sorry for the mega late response.