I'd just like to add some more examples. If you're like me, it takes more than one example to get a non-superficial understanding.
To be [some role]
Forever be the people's guardian angel
To be a teacher [is] simply difficult!
Don't again spend money going to the hairdressers to be a model
Is [a] Sagittarius really suitable to be a lover?
To be a [something]
In fact, I don't want to be a hypocritical person
How to be a loved-by-all good daughter-in-law?
Don't let your imagination run wild, [and] be a pig
In the Forbidden City, to be a cat, is what kind of feeling?
(Or: What does it feel like to be a cat in the Forbidden City?)
Cannot be [some role]
[If we] cannot be boyfriend and girlfriend, can we be older brother and younger sister?
Why [we] cannot be sweethearts, [and] also cannot be friends
[If you] cannot be your own master, [you] become another person's prop
Cannot be a [something]
What is preventing you; cannot be a hardworking housekeeping person?
I am destined to not be a sloth
On the 572 bus, I cannot be an independent-behavior pig.