Some answers

10. Dieter von Isenburg 1460-1461
    Adolf II von Nassau 1461-1475
    Dieter von Isenburg restored 1475-1482


11. The Mainzer Feud 1460-1463
    400 killed on 28 October 1462 and 400 more exiled, including Gutenberg.
    In 1465 Gutenberg was appointed to the court of Archbishop Adolf and given his pension.
    2/3/1468 (or sometime prior to that) Gutenberg dies in Mainz.

By the timelines, it seems that gutenberg was a loyalist to the reforming Dieter and not to Adolf. He was exiled briefly after the invasion, but within four years had returned to court. Perhaps he had something to do with the reinstatement of Dieter into favor as Adolf's heir? And where did he go during exile?

Question:

15. Where did Gutenberg go during the term of his exile in 1461?