How to add a custom read more link in views?
Probably going about it the wrong way, you could either set a custom text field on your node called 'Link text' then output that as a field and check 'Link this field to its node' in views.

Or you could use the 'Link' field type contrib module, then output that as a field, this will allow you to set custom text as the link label, but you will also need to supply the link itself. But this will allow more flexibility.