I have a love/hate relationship with this Stack Exchange site. I love it because it often shows up in Google and I often get excellent answers to my question. But it's difficult to participate in. If you have thick skin and don't take it offense when you are get rejected, downvoted and your posts get closed, then Stack Exchange is an excellent site for you. But if not then I have some ideas what can be improving to make the site more welcoming.
Reputation system needs some change
Early content gets more exposure. Also the good questions are generally asked early. The scoring system based on votes. Content that has more exposure have bigger chance to get upvotes, and since early questions are better and often more upvoted than never ones. This means if the early adopters stop contributing after they made several hundred posts, they can capitalize on their posts and get their daily 200 reputation even when they stop contributing. While new users even if they make more answers don't get enough exposure, because the content is new.
Personally I value 1000 posts with 1 upvote on average more, than 100 posts with 10 upvotes. But in the current scoring system both content worth the same, just because the number of votes. How would I change the system? First I would maximize the score each post can earn in 100 points, and points would be awarded based on teh lower bound of Wilson score confidence interval based on the ups and downvotes the answer get. This means each post start at 0 and after certain number of votes it will be set and will be readjusted as ups and downs come. I would also hide the score of answers and questions and would just use the score internally as an ordering criterion.
Answers worth more than questions. This would mean questions shouldn't worth reputation at all. I speak against myself here since I usually ask questions and rarely answer. But I think as an asker, getting an answer is a good reward on its own. While as an answerer getting internet points is the reward. At least if we gamificate it people would write answers just get to the top of some daily or weekly toplist or such.
Content written in good faith should be valued even if it's wrong
Stack Exchange is the only I stumble upon regularly when searching for solutions in Google. And so far it's the only site I know that shows post score with a larger font than the title of the page. This means getting downvoted or getting your question closed puts a huge shame on your account. And this typically urges you to rage delete your content immediately. Since downvotes and close votes are usually the first votes to come, it can turn off posts that would otherwise come out well, after a time.
Let's discuss questions first. Before I ask a question I always search web for at least 2-3 hours, and ask only if I don't find the answer on the web. I say again: 2-3 hours. That's my personal rule. Even after that I read the relevant SE site's help center too know what's off topic what isn't. And I ask only if I can definitely fit it into an on-topic category. But even after my best efforts, my question often closed. And this feels like throwing me out and shut the door after me. It feels bad, and is it my fault? I will never know, as close votes don't require explanation. And nothing worse than getting punished without reason: you cannot learn anything from it, you cannot be able to make better questions or such. How can this be resolved? Personally I like Quora's system here. They don't have separate site for every niche. Instead they have groups and subgroups the asker must put his question into after it was asked. If the question is off-topic in a group, it will removed from it or will be moved to the appropriate group, instead of putting a [closed] tag on it. If it's too broad or open ended, perhaps it can be put into the "open ended" group or such. And it can happen transparently and the asker don't feel the door was shut on him. Also the answerers can filter questions by group tags to match their interests. I think it's a win-win situation here.
What about answers. An answer can be right or wrong. Wrong answers get downvotes. But downvotes are a form of destructive criticism, you cannot learn from it, because it doesn't tell you what you did wrong, it doesn't contain a proof your answer is wrong. This can turn people off from the site. The fear of downvotes often incentivize people to write answers in comments instead (while it's supposed to be used to ask clarification on the question), because comments cannot be downvoted. Using the Wilson score method, your answer cannot be score worse than 0, even if it attract downvotes. You don't even need to fear from the backlash if you downvote a post.
This is for post written in good faith and not spam or other trolling posts.