Re: You can't get close to people, they might hurt
You're partially right. Opening up to people does put your feelings at risk. But that doesn't mean:
1. People will definitely hurt you, if given the chance.
2. You thus shouldn't allow people in.
You just need to be aware of people and how they operate. They tend to work towards their own self-interest. The vast majority don't set out to hurt people. The hurt comes from them either thoughtlessly saying/doing something, or deciding that causing the damage to you is "worth it".
That last bit might sound heartless, but it might not necessarily be. Say you're dating a guy, and you're not feeling it at all. You want to end it. But the guy seems rather taken with you. Should you string him along? Pretend to care? No, the correct thing to do is to call it off. Yeah, it'll hurt him, but it's more important that you be free to find someone you CAN connect with, and to set him free so he can feel crappy for a bit, and then get back to finding someone who can love him back.
Another to keep in mind is that there aren't just two choices - "open" and "closed". Your choices aren't "totally avoid contact with all people" and "immediately tell everybody you meet everything you know and feel, and hope they don't hurt you". There are various stages of "openness". Most of us start out by, as some call it, "doing the dance". We say "hi", we introduce ourselves, we talk about the weather or the music at the bar. These are "dances", rituals, with standard steps. If one of us decides that we don't really like where it's headed, we can bow out with very little damage inflicted. "Thanks for talking with me - I'm gonna have to head out." "Sure thing." No crippling emotional scarring there. A bit of disappointment, perhaps, but easily rebounded from.

If "the dance" goes well, we proceed on. Talk about something with a bit more heft. Go take part in an activity. Move the relationship along.
Lex