Googling showed me no results on how to use Dotfuscator to obfuscate .DLLs targeting .NET Core 1.0. Should I just use ordinary Dotfuscator version and no special settings for that? Will the resulting obfuscated .dll still be fully compatible with .NET Core?
Since Dotfuscator is a commercial product, you can contact their support and ask about .NET Core / netstandard compatibility. If dotfuscator was able to obfuscate old PCL assemblies, it should work for .NET Core as well.
Recently I've tested open-source Obfuscar with my assembly that targets netstandard1.5, and I was able to use the dll in .NET Core project after obfuscation.