You can pair it with pretty much anything with the correct bluetooth version
PCs definitely work. The Android app and iOS app are usually updated at the same time and you can firmware updated it over bluetooth.
Max SPL is 90 dBA, no idea how they test it can ask next time I talk with them.
No way to do any FR graph that makes sense for a design like this as it changes with azimuth, would be impossible to compare between different mobile speakers due to design. It is interesting as the FR changes with volume due to the DSP. Driver protection would likely kick in at high volumes (lower bass response), and perhaps they also have thermal protection.
Battery operation is noted in the review. It is as stated by the manufacturer in the run down tests, sometimes a little more at normal volume and mixed music.