#where he's astonishingly...possibly to deteriment...permissive

[fideidefenswhore]

Was the young Henry VIII a very friendly and gentle person?

Assuming you mean on a personal level (since, obviously...ordering executions is not especially 'gentle'), that seems to be the general judgement. There's not actually much variation from it from 1509-20s, foreign observers extol his gentleness and generosity and piety throughout the early 1530s, their only specific criticism there is that he's enthralled with a woman of 'bad character' (shorthand for 'low birth').

'the kindest of princes' (Cranmer, 1526) ‘a man of gentle friendliness, and gentle in debate; he acts more like a companion than a king’ (Erasmus, 1529) 'affable and gracious, harmed no one' (Venetian ambassador, 1519) 'He is kind and affable, full of graciousness and courtesy, and liberal; particularly so to men of science (virtuosi) whom he is never weary of obliging.' (Venetian ambassador, 1531)

There's some interesting post-contemporary observations on this matter, too (that have to be considered more doubtful since they're more influenced by hindsight and sometimes, by partisanship); such as:

"her Majesty's father, though otherwise the most gentle and affable prince in the world, could not abide to have any man stare in his face; or to fix his eye too steadily upon him when he talked with them".

And while I won't arm-chair, body-language 'science', pop psych-analyze that one (search results yield that specific source quote to 'narcissism' discussion), since it's neuroableist particularly to suggest an inability to maintain eye contact is indicative of innate deceit/dishonesty ...it is an interesting observation, considering how long he was in the public eye.

'Otherwise' gentle and affable is what's interesting about this remark, really, because are gentleness and friendliness mutually exclusive with a certain self-consciousness? I don't think so, and I wonder if this manifested particularly once he got to the point in a public ceremony/spectacle where he became overwhelmed by the attention and scrutiny, it is not typically how he's thought of but it's such a specific observation connected (but 'contrasting') those specific traits you asked of, I thought it was worth mentioning.

Mantel touched on this,

‘The burden of kingship,’ he says, ‘no man can imagine it. All my life, to be a prince: to be observed to be a prince; all eyes to be set on me; to be an exemplar of virtue, of discretion, of excellence in learning; to have a mind young and vigorous yet as wise as Solomon; to take pleasure in what others have designed for my pleasure, or be thought ungrateful; to discipline all my appetites, to unmake myself as a man in order to make myself as a king; to waste not a minute lest I be seen to waste it; for idleness, no excuses; always alert to prove, always to show, that I am worthy of the place God appointed me … When I was a young man I suppose I showed the calf of my leg to an ambassador and said, “There, has your French king a calf as good as that?” And my words were reported, and all Europe laughed at me, a vain idle boy, and no doubt people laugh still. But being young I asked myself, if God had formed François better than me, which prince did He favour most?’

And I also thought Mantel touched on this (although I can't find it in my highlights atm, so maybe I'm misremembering); I distinctly remember this scene...where somebody is recalling, as Duke of York, Henry was placed on a pony or horse when he's only two or three years old, and this is really his first public appearance, and he's reported to have acquitted himself well, to have been charming and gracious and graceful, even then...but even then, there was always this dark spectre. The timing of his ennoblement as Duke of York was chosen with purpose, it was in the shadow of a pretender. Was there a sense of unease, even then, that he couldn't articulate until later: that behind every smile, could be a knife?

'[Henry VII]'s children grew up in a world of threats, intrigue, and paranoia', '[Prince Henry]'s earliest years were as emotionally insecure as his father's reign was politically uncertain', '"he is so subjugated that he does not speak a word except in response to what the king asks him"'; again, the latter does not match the gregarious (perhaps even, more self-fashioned than natural) personality he's recorded as having as an adult.

The possibility that he oscillated between two opposite settings, and adapted accordingly, back to back (relative isolation and circumspection, to complete immersion in public celebration and celebrity and grandiose openness/friendliness); could account for the contradiction of an "affable" young man that gradually became uncomfortable with the level of scrutiny to which he was held, and maybe even modulated his habit and outward persona to fit what was expected of a king.