Upgrading is always a challenge in this hobby. My best advice is buy a few thumbdrives and test before using your main system. I have a nice I3 HTPC for my main system running LE11.0 and will likely update once I know everything I need to use works. Keep in mind LE is constantly changing and improving so keep informed by checking in here and by all means help support the project with a donation.
You can download the chrome installer here:
browser.chrome
You install from zip file just like any addon. It will take care of the rest.
As for the Custom Audio Device my experience has shown the setting is more dependent upon the HDMI configuration of your TV or monitor. Some of my TVs require the setting and some do not. As for the audio in chrome the process is somewhat involved and I passed on the effort. Some sites on Chrome that have their own audio controls just will not work properly and some even cause browser errors. What I have found that works for me is after launching Chrome I go to YouTube and play any site that has audio. That seems to kick start the Chrome audio system. After that most sites will play fine. Kinda hokey to do every time ya start Chrome I know but seems to work so take it or leave it.
On the bluetooth issue that's above my paygrade.