I haven't been able to figure out exactly what Proxy links and Proxy images settings do and why I'd want to use them. I also see these topics a lot with SSL talk.
Those are explained by Kier in the HYS video here. The relevant part starts around the 2:30 mark. They're intended to help suppress insecure content messages when users post picture URLs and links to sites that don't use SSL. But, they're also handy for tracking outbound links and what pictures are posted on the forum and how many times each has been viewed. Speaking as someone who runs XF on SSL and previously had to deal with insecure content messages, those are my very favorite XF features. Just a wonderful addition to the core.
Remote images are copied to your site. Local images can potentially be loaded faster and if the remote image is no longer valid, you have a local copy of it.
yes, but you can define how long you want to keep the attachment cache. This also helps with SSL to prevent mixed content warnings http://msdn.microsoft.com/en-us/library/ee264315(v=vs.85).aspx
Regarding attachment space, I have over 350K of attachments many large images and disk space is at 40GB at the moment. Point is disk space is not a very big concern at all.
Does the default settings in the latest 1.4 build of: image proxy ticked; and "0" days, mean that hot linked images from other sites get saved on the server? This is what I'd like to happen on my sites due to the X image syndrome.
