Slider Image URL

You can’t obfuscate a link that is publicly available when a page is loaded. What you can do is prevent hotlinking by only serving the image if the referrer comes from your site (try this plugin). That won’t prevent people from stealing your image by inspecting the source code though.

You can move the entire wp-uploads directory to a different path. You just need to specify it in Settings → Media under Full URL path to files. You’ll have to manually move the contents of the wp-uploads folder after changing this setting. This website uses that setting. If you take a look, all images are stored under https://www.onedesigns.com/media/. To do that we changed the setting of Store uploads in this folder to ../media and of Full URL path to files to https://www.onedesigns.com/media. Basically the Store uploads in this folder setting denotes the relative path and Full URL path to files the absolute path. The last setting was necessary to avoid paths like https://www.onedesigns.com/wp/../media (notice the wp/.. part that means to parse to the wp folder and then move one level up again).

Yes. You can use the link post format for that.