To disable autocomplete you can use:
Edit->IntelliSense->Toggle Completion Mode(Ctrl+Alt+Space)
This will also disable it for all characters. This suits me but may not be exactly what you are looking for, VS2013 allowed you to select which characters and specifically Space I'm not sure why this was removed.
To Disable brace completion:
Tools->Options->Text Editor->C#->General->Automatic Brace Completion
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