The other seven deadly sins and some traits like cynical may piss off the clergy but can be otheriwse ignored, prince bishops often have higher opinion by default anyway due to other factors like investiture and never really get strong enough to become a threat since the AI for them aren't as aggressive for nobles and they cannot acquire lands through marriage. Instead try to get: kind, diligent, just, gregarious, and brave. Try to educate your heir yourself and make sure he does not get traits that decrease vassal opinion, these traits are: slothful, cruel, arbitrary, craven. Get matrilineal marriages for your female courtiers as much as possible, especially dynasty members with good traits.

Revoke titles when the opportunity arises. Do not allow vassals to accumulate territory. Only create new vassals on baronie level holdings if you plan to keep the county for yourself. When conquering infidel territory, giving all vassal titles under the count level title to a new vassal will make him like you for granting baronies as well. Be careful giving holdings to ambitious charcters, they will get a -50 opinion modifier of you if you have something they want.

But beware when landing your sons, heir, or any dynasty member, the AI tends to get assassiny and stupid. Hand out multiple titles to your heir as this will help him accumulate prestige, which will make succession easier. This will get your dynasty a little less prestige but greatly reduces the chance of them revolting.- When handing out land titles, keep them down to one title only, unless if it is your heir. To be safer, only give your dynasty members bishoprics, baronies and cities. Even distant relatives have the potential to claim your throne. Be very careful if you give out county titles to your dynasty members. try to find relatively young characters of your religion and culture who have the content trait. when your empire has become a giant sprawling blob and you have a couple hundred vassals, you may want to start creating duchies and handing them out if you have gotten crown authority to absolute (free revocations), in order to better rally your entire empire's troops during war. This may cause you to hold too many duchies. Also, don't create duchies in regions that you plan on being a part of your demesne. Do not usurp titles if you don't have to, for the same reasons as above. Additionally, if you own any provinces within a duchy, the duke or duchess of the region may be upset by this fact. While they give a temporary prestige bonus and casus bellis for quicker expansion, in the long run they cause more instability within your kingdom, as vassals will attempt to acquire these titles via rebellion or some other means. Don't create additional duchies or kingdoms.

Too many held duchies ck2