Hi Michael,
First, I need to clarify something. If you have .es, .it. de, those are not language domains, they are ccTLDs, targeted at different countries. .es is for Spain based sites, not Spanish language sites. If your translations are on ccTLDs, you are sending the wrong signals to Google and Bing. A ccTLD is always geo-targeted to that country and for some of these domains, the language you mean to target is actually much larger than that country. For instance, only half of the world's French speakers live in France.
If you are just meaning to translate your content, I'd suggest moving that to your main domain and putting them in subfolders, so www.domain.com/es www.domain.com/it (for italian, not Italy).
Once that is all settled, linking to the others in the footer is not hurting your link equity, but it isn't necessary either. For translated content, you should be utilizing HREFLANG and the Meta Content Language tag (for Bing) to note to the search engines what pages are translations. Then you simply need to give users a way to change the language either at the top of the page (preferred) or the footer.
If you mean to geo-target (developing different sites to target different countries), then my answers change completely, let me know if that's what you are trying to do here rather than just translate. If you're not sure what to do, check out this tool I made to help you pick the best international strategy. http://www.katemorris.com/issg