There are huge differences actually. A lot of the stuff sounds similar on the first glance, but when looking at it thoroughly you'll spot huge differences.

"She's trying to resign" is about one wanting to do something at this very moment, what one has already decided beforehand. Basically being in the process of doing/changing it. "She decided to quit" is about one who decided to quit, but has not done anything yet to change it. Those are two fundamentally different things. F.e. When I say I am trying to run, it means I am trying to run but cannot do it. When I say I decided to run, it means I am about to do it, but not doing it yet.

"I was overjoyed to join" is about a very happy person to literally connect with another group. "I was happy to get in" is about an only happy person to enter something, but not necessarily establishing a connection after being in that group. Again two fundamentally different things.

"I had envisioned" is to imagine something about a future. "I so admired" is about regarding someone with respect. Again two fundamentally different things.

"ruthless realists" is about having or showing no pity or compassion for others. "Cold hearted realists" is about lacking affection or warmth. Again two fundamentally different things.

"A crying angel" is literally a crying person. But you can also cry happy tears. Depends on the context. "A weeping angel" is someone who is literally grieving and being extremely sad. Again two fundamentally different things.

"gathered them all" has an undertone of randomness in it. You search for it anywhere to find it. "I've collected" on the other hand is about a methodical approach. So you gather cows on a field, but you collect data for a scientific research. You don't collect cows or gather data usually.

"How earnest..." is about showing an intense conviction towards something. "You're serious" is about being honest, telling the truth, being sincere. Again two different things.