Find my iphone features on iphone 6 plus?

IIm using iphone 6 plus and regarding about the Find my iphone, i already enable it on icloud setting.
If one day i lost my phone, can i track it If the phone on switch off mode?

Thoughts on iphone 5S screen size vs bigger phone size?

What are your thoughts on the iphone 5S phone size? I was reading that Apple will release a new hardware upgrade model of the 5S phone size also in the future. I have iphone 6S plus and I like the bigger screen because its easier on my eyes, however I can see the benefit of having the smaller phone for some people because when I had iphone 5S that really fit alot better in my pocket and hand and is really light compared to the bigger screen phones. Just curious what everyone thinks on that size. I think its smart of them to give people that option and upgrade the hardware on that size phone also but I'm curious what the thought are on the big screen vs the iphone 5S size.

Are there any iPhone apps that can help our situation?

My mother and I have been sensing some changes in my younger brother s(14yo) behaviour. The last we heard from him about his new iPhone he got for Christmas, he had downloaded a Facebook app called "messenger" he is always on his phone now-a-days and we can't seem to get through to him when he is angry. We think the causes of him being so angry may be Facebook messages on his phone.
How do my mum and I look at his messages without seeming intrusive.
Are there iPhone apps that you can get to obtain his private messages on Facebook?

I set my iPhones date to Jan 1st 1970 and now my iPhone won't turn on! What do I do?

I was following a tutorial on youtube on how to get more gems on this game, but I got trolled hard, It ruined my iPhone. I didn't know that it'll brick your iPhone until after I did it. I'm afraid to take it to my mom and have her freak out cause I just got my iPhone 6S like 2 weeks ago. Omg I'm freaking out! What do I do?!

Added (1). I'm really afraid to take it to my mom cause I'm afraid she'll flip out on me.

I tried to do an iTunes restore but it won't work. ITunes won't recognize my device

Which Apple Watch should I get?

Okay, I want an Apple Watch. I have no doubt about it. But, I'm confused on which one should I get. I love the gold sport model as well as the stainless steel one. However, I also like the Milanese loop. But, I don't know if both will look good together. Moreover, isn't there a possiblity of electrochemical reaction between the two which may cause corrosion? Finally, is Milanese Loop available with the gold sport model or do I need to get it separately. Also, do you think it will look better than the midnight blue strap(I love that strap too) and can I get the midnight blue strap for the stainless steel model. Also, I have a gold iPhone 6+ so would it more prudent to get Apple Watch Sport gold as I think it might look more appropriate?