Well I think that some of these are not red flags on their own (otherwise not many people would be meeting the gold standard).
I think there's a difference between BRIGHT RED fiery flaming flags, such as insulting you, being nasty when drunk (or sober), preying on your vulnerability or disregarding your opinions, wishes and feelings. Any one of these is a signal to get out. Right now, before it goes further.
Then there are some REDDISH / ORANGE flags, such as being a workaholic, being secretive about finance (or preoccupied with money and cost), or talking about people disrespectfully. These are something to look out for but probably need to be considered in context. For example after being in a financially abusive relationship previously you might expect that person to exhibit some extreme behaviour around finance - which might be secretive, or expecting too early integration of finance, or being wary about things are apportioned.
And then there are AMBER flags, which on their own can be a part of a normal, healthy, long-term relationship, but which if there is a collection of them become overlaid and become red. So an early declaration of love, could simply be due to overwhelming enthusiasm
But put it together with being possessive, wanting to know where you are, criticising your friends / family etc, and they start to become a more significant warning sign.
It is difficult because we are all humans, with our own peculiarities and preferences, and part of creating a relationship with someone else means we have to trust, compromise, accept people's 'faults and foibles. And each of us need to work out what we can tolerate in terms of the 'flags' and what we can't.