Can I output the font with Optical Kerning as default instead of Metric Kerning? Is that Possible?
How do I visually adjust the L+R spacing, instead of metrically? In the tutorials it shows an example dragging the guides for V A but I can’t find where to do this in the App?
My caps are outputting quite small, despite being sized to ‘cap height’ guides?
No, that is a setting in Indesign that can't be controlled from the font. But some people wrote scripts that can import optical kerning from a sample text into the font. But that is not advised as the optical kerning algorithm is context based and thous can produce wrong results.
What tutorials do you refers to?
That depends how you set the vertical metrics: http://www.glyphsapp.com/tutorials/vertical-metrics