Is there any harm in having sex every day? Can we hurt ourselves? Do we have a problem? Do we need to slow down for any reason? We love having sex, it's our favourite thing to do together, but perhaps we should widen our common interests?
Generally speaking, no, there isn't harm in having sex every day, as long as you and your partner are both happy with this, and you're living a balanced life. Having sex seven-plus times a week is considerably more than the average for couples (which is just under twice a week). However, many loved-up and lusted-up couples, particularly in the honeymoon phase, will have daily sex and this is absolutely fine. It's part of a healthy sex life, and reflects the new passion you have for one another as you discover each other.
If you're further into a relationship, a few years for example, and still having daily sex, many would say "more power to you" and "what's your secret!?"
There are several ways to communicate in a relationship, verbally and non-verbally, and communicating and bonding through sexual intimacy is a great way to stay connected as a couple. The only issues would be if one partner doesn't want to have as much sex as the other, then the frequency needs to be negotiated. Most couples have to navigate this area at some point and clear and open communication is the best way to keep both of you satisfied with your mutual needs met.
The other issue would be if your focus on sex was so much that you found you had no other way to relate. Sex can be good for bonding, some conflict resolution, pleasure and fun, but it shouldn't be the only activity you share or find enjoyable together. So while there's no real harm in having sex every day, you should also make sure your lives, and relationship, are balanced with other pursuits and interests together, whatever they may be.
Likewise, if you're single, having sex daily isn't necessarily harmful, however it does indicate a rather one-dimensional approach to life. And add to that, as a single person, the more you have sex with multiple or unknown partners, the more you potentially increase your risk for unsafe or less safe sexual behaviour which is a concern.
Whether coupled up or single, there are a few signs that could indicate your daily sex isn't particularly healthy and may border on a sex or love addiction or compulsion. If you find yourself thinking about sex, planning your next sexual activity or pursuing sex for the majority of the day or night, so that your focus is not on your work or study, or usual responsibilities, this is a problem. If your sex life dominates your thinking and time, so that you skip work, don't pay bills, spend a lot of time on the internet and otherwise avoid areas of life that don't have to do with sex, then this is definitely a problem.
Yes, couples should have a full range of common interests outside the bedroom. If they have this, and also engage in regular, daily intimate activity inside the bedroom, then no, there's no harm. The moment you feel life is unbalanced, however, take some time and make some effort to gain that balance your life as a couple with be all the greater for it even inside the bedroom too.