Functionality such as downloading link click data is not offered if you build a custom report, even if you're looking at a very similar data set and metrics as a standard report. Customization of reports should make things more useful, it should not mean losing functions and features from the standard reports. For example, I built a Page report that filters down to only a specific page type by using our unique attributes set by our pageview tags. I am able to create a click stream or true path, but not see the page click data, which is what I need most from this custom report. I have encountered other functions that get stripped away when customizing reports. Please adjust the strategy to make customization a value add without becoming a tradeoff of basic features.