No idea who wrote this list, but advice columns on men tend to be laughably inaccurate. Like, open-mouth-guffaw inaccurate.
In this case, not-so-much. The writer seems to have a nice handle on suspicious male behavior. I know because I'm a suspicious-ass male.
Number 8 kinda pisses me off cuz even though they may be right, if the guy is romancing you then he's working at the relationship. Don't waste your time on suspicion. Just dump him if you can't trust him.
Number 9 is the best way BY FAR. If he's cool with not getting some then he's most likely going somewhere else. Or he's very very old.
In the meantime, click and learn.