Curation no longer means anything so skip it. Publications? Meh. Medium announced previously that they are getting away from publications and working towards focusing on indie writers instead so while still around like shopping malls, their time is about up. REAL followers will get your views and reads.

Quality and quantity are both needed. Long or short? Meh. Medium states that the golden number is 5-7 mins but from everything I've seen it's more like 4. Top writers are on their way out. And as for self-publishing, if you have enough followers then fine. If not have a half a dozen smallish pubs to submit to and spread your work around. Once you hit 1k of REAL followers you'll be less reliant on publications.