Do you think my rules of social etiquette are too strict?

No, I don't think it's too strict. Being modest is what makes a person classy.

I personally am somewhat like that. I don't go around telling people about myself unless they ask. Even when they do, I often do not go into details because I already feel like I have a hard time explaining and/or defending myself if they believe a preference is odd, so I'd rather just not get into it.

Also, from experience in the past, I realized the ones who do not know a person often cuts them short when they try to explain themselves, or they'll listen with some divided attention. They often will not care about what I actually have to say and are indeed trying to compete and compare.

i dont think so

God forbid my coworkers know what I like to do during my free time

To be serious, only disclose what you feel comfortable sharing with others.

I mean people just ask questions that seem too personal sometimes just to make conversation. I have done it with no bad intentions.  But it's always best at work not to make close friendships 

I'm not that guarded or that suspicious of people, so no, I wouldn't make these rules for myself.

None of that is necessary if you do background checks and have your coworkers sign non-disclosure agreements.