You have the questions and we attempt to answer them to the best of our abilities below.
This is a question that only Sony could answer, and like any console manufacture, they're sure to keep things quiet until they feel it's the right moment to make such an announcement. However, with the current success of the PlayStation 4, it would only make logical sense that a PS5 would be Sony's next juggernaut console.
It's important to consider the current PS4's lifespan before making a prediction on when a PS5 might release. Sadly, it's not easy to estimate right now, however, 2022 would seem like a sensible prediction. However, it could be much sooner or even later depending on Sony's strategy with the PlayStation 4 moving forwards.
Unless the world changes dramatically within the next 10 years, which is quite possible, then the PS5 is more-or-less guaranteed to have physical media. Many countries and regions still have access to sub-standard internet, and this is likely to still be an issue in the near future. Even if everybody could access super speedy internet, there would probably still be some kind of demand for physical media. Another scenario could be that a PS5 would have two editions, one of which might be digital only (perhaps with a larger hard-drive to accommodate the downloads, it could be slimmer, too). If we had to place a bet, then we'd put it on the PS5 having physical media capabilities just like the PS4 currently does.
This isn't easy to predict, far too many factors are involved. It would make sense that Sony would want the masses to afford such a console and a ballpark sum would be $599.
When you look at what Microsoft did with the XBOX One, it's easy to see that changing a brand-new can certainly be somewhat disastrous. The progressive style of Sony's PlayStation brand is easy to grasp and gives you that feeling of progression. In other words, it would be very unlike Sony to not continue onwards with a PlayStation 5.