Well if you built the app then I would suggest add a means to allow the community to flag inappropriate messages, then start banning the responsible users.

I was in your exact same position a while back, so I went and got a Computer Science degree. Now I can program anything that I want. This took about 3 years so I doubt that this is a viable option for you. I will say though you either need to get some money from somewhere, learn to program or find a co-founder and give up half your equity. Otherwise just give up

1. It solves a problem for the heaviest mobile using demographic (sexting, snooping parents, etc)
2. Its social, social apps that are engaging have the potential for exponential growth
3. Media exposure via controversy and bloggers
4. Solid user experience
5. They had technical co-founder (this is a big one) this help them get to a point of viability
6. Funding, they had access to money when it was needed
7. Luck, there is always a certain level of randomness, I guarantee that you could create an app that follows all the same steps as SnapChat and go completely unnoticed

So I joke with my friends about this all the time. When I hear about a high school kid building some million dollar app, I say if programming was as easy as it is now when I was 16 with all the free time I had I would be a millionaire too. If you have the money to invest in a freelancer and you have a well thought out idea then that is one rout you can go, but this might be a good time to learn some development yourself. If learning yourself is not an option then I might suggest perhaps you might want to entertain the idea looking for a technical co-founder in you network. I know some people oppose adding a co-founder at this point but I think there are a few thing you should keep in mind. Depending on how validated your idea is already you probably have to do quiet a bit of iteration and feature changes to get to MVP and that will cost increasingly more money. The other thing to take into consideration is your age, some investors will be apprehensive towards investing in you (not your idea) so to over coming that your app will probably need to be further along. Both of these concerns are addressed by bringing on a technical co-founder, yes you will lose some equity but what good is having 100% of nothing.

Demographics aside, one of the most compelling factor in making your decision is your available resources (assuming a web app can support the desired feature set). If you are building a desktop app you have take into consideration the fact that you will only have access to customers who's operating systems you can afford to support. Take into considerations OS updates, hardware specific issues, and software interactions. If you build a web application you only have to worry about the self contain environment of your server, and browser support. So if you have enough developers to overcome the issues associated with a desktop app then go for it.

You would have to apply for non profit status, which means you would have to incorporate as one of the 29 different 501c classifications. Since I don't know of the details of your business model I would not be able to say for certain, but it is contingent on your company fitting the description of one of those 29 classifications.

Yes this is indeed possible. Like most things in business this is a cost benefit analysis. A company will assess if the cost of acquisition outweighs the cost of implementation. Also the only way your app would be a candidate for acquisition is if your product is truly aligned with their overall strategy. The best you can do is patent and copyright where appropriate, and insure that your product is so far ahead that it would not be worth playing catch up.

The short answer to that question is to ask yourself or your firm what you are already good at, like what really are your core competencies. Once you have compiled a list then look for other industries and or markets that you can apply those competencies to that don't have insurmountable barriers to entry.

Yes you can use https://www.flinto.com/ , or you can use draw.io that is a free google docs plugin

I don't want to be a wise guy, but I think the Internet would be a great place to start; particularly social media. What ever your product or service is I am sure that it resides in an industry, and I am willing to wager that industry has thought leaders. I would start seeking out thought leaders in your space and come up with a short list that have a reasonable social media following. The clout of the people on your list should coincide with your ability to compensate them. The benefit of using established thought leaders is that they are already tied into the community that you are trying to win over, and your thought leader probably already has the trust of your prospective customers. I cannot however stress enough the importance of due diligence prior to reaching out to a prospective thought leader, because you are trusting this person with your brand to a degree.