one item that has struck me is the natural inclination to fall into being a nice guy to avoid conflict, and to please others. this is a big part of my upbringing as well.
I had that in my upbringing as well, and conflict was a no-winner for me considering the people I was dealing with, so I played the "nice" game too. It can be an effective strategy to avoid conflict, but if it is practiced too much you can also feel smothered/powerless because being yourself (especially when sharing your insights or sticking up for what you think is true) will often butt heads, and some other people will take it very personally, yet not speaking up leaves you no voice in the world...
it seems like its a blocker often for me, and i overly consider others needs before moving myself forward, or seeking approval behaviour.
keen to know others experiences, and what others have done about it if they felt it was an issue
I didn't really start to really break out of it until adulthood, when I realized I was really unhappy and didn't want to live that way anymore.
To be honest, the worst period was the initial period, because I had little experience in constructive conflict (having avoided it) plus the initial shock of people who had one image of me in their heads. You basically have given people an inaccurate picture of the totality of you by being nice all the time, so some will be shocked and even put off when that image changes .... although to you, you are simply being more honest for once.
I hated to burn bridges, but at some point I learned that some bridges are worth burning... and it wasn't me who was doing the burning, it was the other person who might be upset over what I was being honest about. If they can't handle me being honest, then there's not much of a relationship there. So there will be a number of "fake pleasant relationships" that might disappear once everything gets shaken out, but the real relationships will endure.
Basically you need to strike a balance in your presentation and also have a goal in mind for yourself -- you're not just being honest to shake people up, you are being honest and risking conflict in pursuit of some goal (that you will determine for that situation), and so since you know why you're speaking bluntly, you know better when to do so. You still have all the insight that you have gained from probably being a good listener and someone who is not naturally aggressive, so that can be used to, in order to interact more maturely rather than using scorched-earth tactics.
There's also a general shift in psychology when you really embrace your adulthood and approach your parents and their generation more as peers than as authorities. Some people make that shift easily, some don't. But desiring for these folks to approve your choices at some point would have to take a back seat. Not that people don't want parental approval on some level, but in the end it becomes kind of a cherry on top thing, and even when you're getting disapproval, if you know what your goal is and what things are important to you, then you can prioritize those instead. At that point you really become autonomous and stop people-pleasing.