I couldn't find stats on most recruited, most killed, most used, most spoken to, or most romanced ORIGIN companions
I can't vote on this, each category is different.

Most recruited for me would be Astarion and Gale, they are the most useful for my playstyle.

Most killed would be Shadowheart for the simple fact that I don't like when certain characters seem to be "expected" to be in my party . I don't mind her as a character though.
In an all custom party, Astarion always dies in the first meeting because he attacks me.

Most spoken to, probably Lae'zel because I like her the best.

Most romanced would be none of them because I do not have any interest in pixel romance in any game, and I roleplay characters with more important priorities.