Presto, fra due giorni.

Your sentence if perfectly natural. It needs no change. Any examples I've seen or could come up with are no more natural.

I will give a short practical answer: Use crevice. Don't use fissure unless you know exactly why you need to use it. Crevice is more general purpose, fissure comes off as more technical.

No. It means the opposite. It means to put someone/something in control. You are putting them in the driver's seat of the car (metaphorically) which allows them to control the care and everything in it.

"How so?" can be used in any situation, but take note to the following: It is usually a way of asking for more details. You are essentially asking someone to explain their reasoning or source of information. If is often used to express that you have some doubt about what they told you, which is way trust and body language are important. Friend: Hey, Erkan, what's up? You: Not much. Friend: Did you hear? The boss is giving all of us the day off today. You: (slightly bewildered) How so? Hope this helps. Good luck.

If you want to be absolutely clear you can just say, "I will pay for it." If it is more formal and business-like, "I will cover the costs." Most common: "I will cover it." or "It's on me." Fits situation #1 and #2. The only thing to be sure of is that they know what you are paying for. If you want to be clear just add more clarity. Don't be afraid to say it several different ways: "Don't worry about. I will cover it. It's on me." and you could add to be sure, "I'll pay for the meal guys." Situation #3 is a bigger deal and so you might want to simply include the thing(s) you are paying for. "Let's go to the theater. It's on me! I'll pay for the tickets."

The firest one is natural. The second one that uses "tell" should also include a direct object. As in: Didn't he tell _you_ where he was going?