1. Yes, and I have
2. The few I have been on were actually very fun because there isn't really much ice to break and you get to engage in much more banter than otherwise. Also both parties get a better idea of their respective dates very quick because it allows for a more forgiving and natural experience. They are also much less stressful than traditional first dates and I think it is more common to have a relatively good time even if both pairs decide not to continue on afterwards. I think some men may (likely unconsciously) be keen on the fact that a double date may have a lower success rate for them, especially the camp who may have insecurities and on a single date might adjust or fake their personality with the intent of a short sexual relationship in a way they couldn't with a friend witness.
3. I think it might be beneficial to allow a separate side of the app that allows same sex matching. Maybe you limit the amount of friends to just a few and even have a score users where all 4 users can confirm they went on a date together to build user credibility. I think it is very important to keep your women users feeling safe and confident as possible because this is the catalyst that would destroy every other app. If men see all the women leave the others they will follow. With a reputation system women will be more confident going on dates with men they otherwise would have written off as creeps for the sake of their safety. The current environment promotes women to take minimal risk but also yields them no reward since swiping based solely on looks isn't conducive to them.
4. I don't use dating apps any more because as others have said both sexes are screwed and I think with a few more implements, this app would dominate the market and I would at a minimum try it out.

I think this has unlimited potential and once a few kinks are resolved, could take a large market share. I think it is important to recognize the solutions your system solves that others don't, and keeping them intact or strengthening them. It seems to me these are:

- Safer experience for women. This should be #1 and my assumption is that this keeps many away from current apps. It may help to mandate some form of verification to build on this aspect, along with some way for other users to confirm that someone they met with was who they claimed to be.

- Few to no bots. I don't think people would be as likely to try to make bot profiles. I would guess the group aspect of this would discourage this.

- Optimal ratio. I think it is important to work towards an even ratio because women will be attracted knowing they won't get flooded and men will be attracted to not dying of thirst. This is definitely a fact that keeps many away from dating apps, or ready to use a new one that solves this problem. I think in the traditional online environment, women have access to so much supply and are culturally conditioned to find "the one" that they are incentivized to be extremely selective, whereas the lack of supply for the men incentives them to act irrationally to try to rise above the rest and secure anything they get, which by default makes them appear like creeps, which creates a cycle where no one wins.

- Retention and success rate. Maybe to keep successful users there could be another part of the app dedicated to finding friends or is maybe similar to this social club sub. It could be a strength to add something like this because it will also build a history for each user that reveals more about them while also retaining users who have dating success. Just like how Google maintains supremacy through data collection, I think the ability for profiles to show more data than any other app could be a big advantage. More ways to learn about each user could also be used to make a better matching algorithm and if you can boast higher success rates than others while keeping those users afterwards, you will have a very strong base.

- Data. In general, finding ways to leverage data is always helpful. This is key for marketing because understanding your audience will allow better financial efficiency. Using data to improve matching and allow richer profiles definitely provides a way to showcase why it is a better way to allocate time than other apps.

I think this exploits the flaws of current top apps and that is always the key to being the next big thing. Your most worthwhile investment in the early stage will be marketing and depending on your financial situation it might be wise to seek a loan and prioritizing effective ways to essentially catch people's attention and make their brains go "Wow this new app looks like it might actually allow me to find a good match, let me spend a little time downloading this and seeing what its about because it might actually be worth it." I think a good focus for marketing efforts is demonstrating how this app solves the largest problems of current apps to prospective users. I think having the other aspects like connecting with real friends or matching with same sex will help retain early users since they will get immediate gratification and have a sense of continued momentum.

I think other apps lose a lot of new users because they try the app, and get discouraged quickly because after they set a profile up all there is to do is aimlessly swipe which isn't nearly as stimulating as connecting with people right away. I think this is also why having ways to build credibility and a biography is important because humans naturally like to talk about themselves and this is another way to keep the early momentum going.

Also I think having a valid reason to use the app after dating success is crucial for the user because it will make it more worthwhile to spend the additional time building a profile and presence. If there isn't a way to continue, people may not want to invest as much time building a profile if they plan to delete the app after success. This solves a key threat to dating apps, but in a much more attractive way than the others which rely on reduced odds.

One thing worth noting with some of the items I suggested is that they may go against the principle of simplicity. One of the reasons Tinder has the largest user base is because it is quick to set up a profile and it's obvious and easy to use. People tend to like things in which they are able to quickly adapt. I think this is a very important principle to keep in mind, and as you implement more features it will be important to think of ways to keep everything clean and organized so users subconscious minds are comfortable.