Playing as Carlist Spain is quite an interesting EU4 looking experience. However, even with keeping the maximum infamy reduction bonus all game by rivaling all of the world it still feels quite impossible to complete the journal quests. Starting with the requirement to conquer all of great colombia and mexico while having to erase them from the map completely in the span of 10 years is impossible. I understand that this kind of gameplay realistically will make you live in the pariah state. However it is impossible even in that, even in breaking wars into several smaller ones and not fighting any wars apart from those in america, you still go through the cap instantly and the whole declares on you.
Maybe it would be possible to solve it by giving more time to complete for the infamy to decrease or giving some infamy reducing event when completing the previous mission, provoding some aditional tasks or costs. Or perhaps by letting player to compelete the grander reconquista without completing all of the conquests. Or at least by allowing to puppet the states instead of having to annex everything fully.