Elsevier submission portals (normally) have a link to your Orcid number. Regarding this, is it possible to add your submitted papers to Orcid, directly by a link?
No! Unless you uploaded a copy of your submitted paper to public preprint server like PeerJ Preprints, ArXiv or BioRxiv. If you uploaded a public preprint you can add that to your ORCID profile.
Extra note: About your published works, as you know, you can add your publications from any publisher to your ORCID profile (after you sign-in to your ORCID account) by clicking on "Add Works".
More information is given here: http://orcid.org/blog/2013/12/05/i-claimed-my-orcid-id-now-what
I'd recommend the CrossRef Metadata Search as often the easiest method of importing one's publications, provided those publications have a registered DOI.