Do you see any advantages to switch to 64-bit for this?
Probably not.
While I agree you probably won't notice any advantages using the 64bit version of MC, any 64bit application is going to have better memory management, so it could help in your DSD128 issue. Of course, if you use any 32bit plug-ins, VSTs, etc., you will need to stick with the 32bit version for compatibility.
Besides, exactly the same Library Backups work with either 32 or 64bit versions, so you could switch to 64bit to try, and if you had issues, switch back to 32bit. That isn't going to affect your music files, unless you do something silly in the Library.
I have also tried bought DSD128 files played direct. They also create those "tics", so I can't say that pcm -> dsd on the fly is worse.
If you are getting tics when playing DSD128 files directly, then I would look to solving that issue first, rather than upgrading your PC. That could be caused by buffer sizes, or other issues. There are lots of threads on similar topics. There was some discussion about the different methods DACs used to decode DSD some time back. Something about one bit decoding versus some other method. Could it be your DAC that is causing the issue for DSD128 files?
At the same time I am very happy with the dsd64 conversion from pcm. To my taste it sounds better in my set up.
Some people do seem to like the tone of DSD files decoded in their DAC, rather than PCM files decoded in the same DAC. I believe some DACs use different decoding methods (plus different algorithms of course) based on the format they are decoding. It might be possible to tweak MC DSP setting to make PCM files decoded in the DAC sound as good as DSD files decoded in the DAC, but testing that would take some time and fiddling. So that might be something to look at after fixing the tics on DSD128 files played directly.
EDIT:
Awesome Donkey has got in a post while I typed.
The other issue with gaming laptops, with more powerful and hotter CPUs, is that they will make more noise keeping them cool. Some of them, lots more noise. Not good for listening to music!