When using Visual Studio 2017, with roslyn, is there a way to enable requiring the "this" keyword for all calls to methods inside the class, and class variables?
I'm trying to accomplish it through the creation of a new ruleset but I'm not sure if that is the best way, I can't find that rule to enable.
As Dai mentioned, you can use code style (you can find it in Options under the editor settings for the language). You can set it as None, Information, Warning and Error.
Your settings will be on an editorconfig file. The current version of Visual Studio (15.6) uses this as an editor feature and will not be enforced at build time. That will be a feature in 15.7.
In the meantime, you can use the StyleCop.Analyzers on your projects.