Emms volume + csharp syntax highlight

So, a couple of days I decided to install Doom Emacs and so far I really like it. I have installed the packages Emms and Csharp-mode, but I have a few questions. 1. Is there any way to get syntax error highlighting in Csharp-mode like in C mode when editing a .c file? I'm still new to C#, so I want to know if what I'm writing will fail to compile or not without actually having to compile it. When editing a .c file I see like a check mark in the bottom right corner when there are no errors, but when I'm editing a .cs file there is nothing and it says "Flycheck, no checker" 2. How do I adjust the volume of Emms? When I do 'M-x emms-volume-raise' it doesn't raise the volume at all and I can lower the volume to 0% but I can still hear the music. I'm using Gentoo with Pulseaudio. I have the alsa and sound USE flags enabled for Emacs. Any help would be greatly appreciated!

For c# I think your best bet would be the OmniSharp language server [https://github.com/OmniSharp/omnisharp-roslyn](https://github.com/OmniSharp/omnisharp-roslyn)

I have tried the omnisharp package, but all of the M-x options with "omnisharp" disappear as soon as I restart Emacs. Setting a hook in my init.el file results in a void variable.

> When I do 'M-x emms-volume-raise' it doesn't raise the volume at all and I can lower the volume to 0% but I can still hear the music. I had the exact same problem on my Arch. If I remember well,[ I have installed this](https://github.com/flexibeast/pulseaudio-control) and am using that one for the control.

Works like a charm. Thanks!