Are the majority of Muslims disbelievers due to the explicit cursing of religion they witness in their societies? And do the examples mentioned in the question – such as jokingly saying "Allahu Akbar," or excessive love for children, or abandoning prayer, or cursing religion, or jesting about religion – constitute disbelief? And is he who does not declare the disbeliever to be a disbeliever himself considered a disbeliever? And what is the ruling on jesting about religion, and what is permissible and impermissible in it? And is it obligatory to inquire about the ruling on an action, if it is unknown whether it constitutes disbelief or not, especially with the fear of getting carried away by obsessive whispers?

What you mentioned, that the general Muslim populace insults religion or that they are disbelievers, is not true. The fundamental principle is that most Muslims revere their religion. It is not permissible to declare someone a disbeliever except with absolute certainty, and declaring entire societies disbelievers is a heinous extremism. All the doubts you mentioned do not constitute disbelief, except for explicitly insulting religion or God. What you mentioned is merely a whisper (waswas) that must be repelled and not indulged in.

As for the rule: "Whoever does not declare the disbeliever a disbeliever," it refers to those whose disbelief is certain, like Pharaoh and Abu Lahab. As for someone whose disbelief is not confirmed, declaring them a disbeliever is a great risk. Avoiding jesting with religious texts is good, but it should not lead you to excessive rigor. In conclusion, you must avoid whispers (waswas) and extremism, and strive against your own self in this regard.