To me, a game like this is all about fostering your imagination, thinking and delight at the narrative as well as a sense of accomplishment at having mastered the game dynamics. To the extent that reloading promotes those 'benefits' for the player it is, as singleplayer strategy/rpg game, completely legitimate and even advisable within quite narrow limits.
With complex games like this one, reloading is IMO essential when you are first learning the game and the specificities of how the myriad things work, for example the inheritance laws, combat, the storylines for complex contingent things like plots, etc.. The available resources for the player (manual, wiki, forum help) are not always perfectly clear, despite the fact that the game is algorithmic (meaning that there IS a binary answer to any question that can be posed, assuming all relevant values are known), and no I don't find it plausible that the character in the game would do something like press a claim for his spouse without understanding the consequences of the inheritance laws.
So in sum: when you do something stupid, and in particular when that is a reflection of not being completely familiar with the game mechanics, NOT reloading, and instead subjecting yourself to a restart (which will often involve replaying long periods of tedium) is I think a pretty good way to cause you to lose interest in the game and thus, cheat yourself even more.
But beyond that, I don't see the point of reloading simply because you didn't like something or found it to be 'implausible.' That I think is intended to be part of the game, in that history itself is full of some pretty wild twists and turns and watershed moments where fortunes swung from wonderful to terrible or vice versa. I agree with several previous posters that "rolling with those punches" is part of the fun of the game.
So in sum my philosophy:
1. When learning or relearning a strategy game, reloading because you made a decision that you didn't actually understand is a smart way to NOT cheat yourself
2. Once you should know better, committing #1 simply to get a 'better' outcome is likely to start to take the fun out of your game and cheat yourself
3. Reloading habitually, simply for the sake of a better dice roll or to avoid what you thought was a simply implausible outcome is very likely to cumulatively take the fun out of your game and cheat yourself.