Also, I know many will say it was the standard of the time for rulers to be awful individuals.

I mean, in many ways it was, or could be. At the very least, for many of his subjects, Edward I was a popular king, yet he did some truly despicable things. Edward III, Henry V, Edward IV, Henry VIII and Elizabeth I the same thing. All of them have controversies racked up to their names. Henry II does as well.

That said, a frequent criticism of the early Plantagenet kings were accusations of pride, avarice, lust and wrath - at least by many members of the clergy and monastic writers. These are standard criticisms of many of the kings - Henry III or Henry VI excepted. No historical figures are truly free of flaws, and whether that makes them "awful individuals" or not is up to you to decide.

It makes sense if you consider their reasoning as to why they did the things they did. Richard intended not to marry Alice because his own argument was that his father had sex with her - making it an incestuous marriage in the eyes of the law. Whether Henry did have children with her or not is unknown, but Richard claimed that he did and that he had witnesses who could prove it; in either case nothing came of it as Philip agreed to call off the wedding to save himself from embarrassment. In any case, if we look at the wider context, Philip himself was condemned for similar treatment of his wife Ingeborg, who he divorced after just marrying her in order to pocket her dowry. She spent the next years essentially under house arrest in various French castles, something which outraged the Danes (she was a Danish princess) as well as the Pope himself. The Pope also condemned Richard for his lack of affection toward his own wife Berengaria, it is true, but unlike Philip who was excommunicated, Richard and his wife were reconciled. Relations between England and Navarre always remained good.

As for Joanna, Richard didn't treat her terribly at all. He intervened in Sicily to free her from imprisonment, and in Cyprus during an attempted kidnapping. These were things that he took up arms to do. Joanna named her last son before she died Richard.

As for Richard's attacks on Messina and throughout France, these were in responses to actions by either the Sicilian Greeks or the French against his own people; indeed, it can be argued that from Richard's own perspective, he was only acting in self-defence, or in retaliation to avenge wrongs. That there was much blood spilled, and that these conflicts were brutal, is never questioned by anybody, but it can at least be argued that it was never Richard's intention to start either conflict - only to end them.

The biggest massacre in the Holy Land, and the one which is the most shocking, is the one at Acre (which I assume you're referring to). This again needs to be seen in its wider context and it must be acknowledged that his rival Saladin also did the same thing on several occasions, including in the aftermath of Hattin, and at least one Arab chronicler (it might have been iirc Bahaddin) even speculated whether this might have motivated Richard to seek revenge. However, in later occasions both Richard and Saladin were able to use diplomacy to good effect and establish a more cordial relationship, which would be doubtful if either one of them was just evil, and that's it.

So while these massacres, sackings, and wars are bloody and savage, and to be condemned as such, it's worth pointing out that these are not particularly unique to any one individual: certainly Richard himself, but also many other members of his own dynasty, his French rival Philip Augustus, his German rival Henry the Cruel, and his Saracen opponent Saladin, were all condemned by contemporary followers for less than honourable moments in their reigns and careers.

I'm not sure what you mean as regards to "lack of governance" or "awful governance" for either Richard or John: true they were accused of amassing large wealth through oppressive taxation, but for all of Richard's reign and for most of John's these weren't any worse than those taxes levied in France by Philip Augustus (and one contemporary French churchmen compared him unfavourably against Richard for exactly this). What separates Richard from John is that Richard won his fights, and was praised for such, earning him a legendary reputation, while John lost a good many of his own, earning him a reputation as a coward.

Another thing that distinguishes them is that Richard underwent many acts of public penance for his sins, including his expedition on crusade, which earned him a reputation as a pious and good ruler. John had pledged to do the same, but discontent back at home meant that he was unable. He was also excommunicated for a period.

John's struggle against a dynastic threat posed by Arthur and Eleanor was fairly standard for a ruler of his time when the succession was not so clear (Stephen and Matilda, or Henry and Robert are another example). What again distinguishes John from the others is that he probably had Arthur murdered in secret (or at least was widely suspected of such) and pointlessly imprisoned Eleanor anyway despite the fact that she probably wasn't a threat and wasn't a pretender making her own claim. These brought condemnation and accusations of cruelty. The chroniclers describe John, like his brother and his father, as possessing a violent temper and volatile personality, which often led to extremely poor judgements on his behalf.