For me it would be:
1.) My own insecurities, feeling as if I am not good enough, smart enough, or financially secure enough for someone.
It's easily rendered though. Insecurities can be worked on, even checklisted daily. Financially speaking, there is always education, online or on campus, you can always progress outside of what your work situation is. So don't think that you are stuck, you never need to feel that way
2.) Distrust, I would find it difficult to trust that someone would not cheat on me.
This is why it's good to be friends for a bit before dating, you can always try dating, but for what you are describing it probably needs to be someone you can warm to first and find out if they flirt alot etc with others.
3.) Clingy, I have very few friends, and fewer that I actually get to spend time with, someone interested in me would have to put up with my desire to include them in my hobbies, from gaming to recording music.
That is fine. Being clingy is actually pretty normal, most couples are on some level otherwise they wouldn't be in a relationship.
4.) I also have little tolerance for things like smoking and drinking. It would be easy to find a non smoker, but a non drinker is noticeably more difficult, especially so if you dont have an interest in highly religious people, and those people may still drink.