1)Norse factions (Jutes, Danes, Geats) do not get weapon damage bonus to their admiral's bodyguard unit when the admiral has zeal more than 3 (when zeal is less than 3 there is no weapon damage reduction either). Roman admirals work fine, I also tested Franks. It is a shame this happens to Norse factions who are supposed to use navy a lot.
2)The carpenter building of Romans is supposed to provide hull strength bonus. Seems like the bonus does not work no matter where the buildings is built (tried many provinces like Salona, Ancyra, Constantinopolis). This bug is reported in multiple other posts too. Affects both ERE and WRE.