Is my iPhone tapped?

For the past few weeks, my phone has been really weird. Every once in a while, after I get a text or sometimes completely randomly, my phone will make 4-5 short vibrations quickly in a row. It feels like the fake home button on the iPhone 7, but I have a 6, so it shouldn't be doing that. The vibes also are throughout the whole phone, not just in the home button area.

Now what really got me is that I just turned on my phone, and it did this thing where some of my apps turned grayish for a second, like when you tap on them, they turn darker for a second. Like four of my apps did that really quickly, but none of them opened. I double tapped the home button but there's nothing weird there, my recently opened apps are just how I left them.

Right phone company and or plan?

My daughter wants to lease her iphone however she will be leaving our family plan and company to do so and I'm worried about her monthly phone bill being too high. She makes two hundred a month and I don't want to switch phone companies. Is there anyway or plan she can get on that won't be so high for her?

Is my iPhone water damaged?

I have an iPhone 6S and it was under jacuzzi water (about 6-7 inches) for about 10-15 minutes. I'm drying it out with rice. What are the chances of water damage?

Added (1). The jacuzzi wasn't going at the time of drop.

Added (2). When I got it out of the water, the Raise to Wake thing was working and nothing seemed wrong with it. I shut it off before putting it in the rice.

Added (3). It's gone.

Is it worth it to get an iPhone just for the camera?

I have a couple cameras, my best being a Nikon D5500 with a few lenses, but I don't always have it with me. IPhone cameras are really good, but I use a Samsung Galaxy and the cam era is trash. Do you think it would be worth getting one to have as a quick to pull out camera?