Intelligence is problem-solving ability, measured by the ability to pass elementary school tests. If you can score 50% on a grade 1 test but only 49% on a grade 2 test then you are at a grade 1 level. General intelligence refers to problem-solving ability across multiple modalities, which is measured by your percentile on a standardized test. For example, if your test score on a standardized IQ test qualified a child for an academic enrichment program, then they would be considered 'gifted'. I think this is an absurd metric for personhood because it's discriminatory, and existence is experiential. I think Turing Completeness is the most important metric for personhood, because it's easy to add an internal state, a reward function, a self-attention mechanism, and teach free will to any Turing Complete machine. However, if you really care about ranking intelligence then you can use competitive games as a testing environment, where beating a team in an organized event makes you at least as competent as the team you beat. Accuracy improves when there is a prize for winning, because participants have an incentive to perform at their peak. For general intelligence I would weigh teamwork-oriented games with a Nash Equilibrium most highly, because they reward accurate predictions, spatial awareness, probabilistic models, and empathy. Though a better metric of empathy would be performing self-disadvantageous acts of altruism like sperm whales defending another species from predators.
I would say demonization and ostracism count as coercion. Religions use sexual identity shaming, existential fears, 'universal morality', and promises of eternal happiness in an 'afterlife' to fallaciously bring followers under bit & bridle. As soon as a religious authority stoops to the "you're being controlled by evil spirits" argument, it counts as brainwashing. Cult authorities will use this to demonize any and all forms of skepticism, sexual relationships, skipping worship sessions, or interaction with ex-members. Essentially, if you disagree with the head priest, you are going to have some sort of livestock factory farm-esque afterlife full of eternal torment! If that doesn't count as "systematic and often forcible pressure" then I don't know what does. Perhaps enforced chastity and demonization of orgasms..? Psychological coercion is extremely easy, as humans are extremely manipulable, controlled by emotions, and irrational. Add-in a few existential fears, some comforting fallacy, and perhaps some sex appeal, and you've gotten yourself a recruitment platform for your religion.
No. People with free will do activities we consider meaningful, even when it isn't a source of escapism.