Emulator

The hotkey bug is something everyone's been running into recently if they've been using Dolphin since before a certain revision (probably the wxWidgets 3 update, but I'm not 100% sure). Easy fix, though: go to Options > Hotkey Settings and re-set every (and I mean every) hotkey. Setting them to the same keys they were before is fine.

As for the sound issue, I'd like a list of games that you're experiencing issues in. If that's every game you have, list 'em all. But, since I have no such list, I'll be much more generic with my advice:

Every game seems to have occasional audio pops and bits of garbage noise, as well as bigger sound issues (music/sounds cutting out or not playing, or even causing crashes/hangs due to errors in DSP emulation).

Using DSP LLE alleviates some of this, but a) it takes a ton of CPU, making games unplayably slow on most computers, and b) if your computer can't run a game with LLE at 100%, the audio's choppy, playing full-speed in occasional snippets, instead of always playing the music at full-speed regardless of emulation speed as HLE does. (There's a good chance you already knew all that, but I'm just making sure.)

Switching audio backends can help - these vary on a per-game basis for how well they work.

Oh, and FYI: the Resident Evil games (since I seem to be the only guy that doesn't have them) have a plethora of sound issues, and LLE doesn't fix them, so you'll just have to deal with it for those. (There's an issue somewhere in this issue tracker for them, but I've got things to get to, so you can search the tracker yourself.)

I think this is a duplicate of issue 5057 (DSound problems)