Can I recover a video I deleted?

Today, I went out to some natural springs with my friends. We were having a good time (while one was recording) when I slipped and almost fell 10 ft head first towards some rocks. We caught it on camera but my friend accidentally deleted it. I have a iPhone 5 running iOS7, if I update it to ios8 will I get the recently deleted folder? Or does that start after I update.

Basically, I want to know if I update to ios8 will I be able to get my deleted video.

Iphone's other takes up data?

My iPhone is telling me I only have 1.4 gigabytes left on it and I've used up 10
The cause of this is "other" which I've been told is corrupt programs and stuff left behind, iPhone users know what i'm talking about,

Can somebody who has had this problem and solved it, help me please?

There's no way in hell I've used up 10 gigabytes as the picture shows.
When I synced it to iTunes it showed the #1 cause as "other" and 5 gigabytes being my documents and such,

Please tell me there's a way to clean my phone and get rid of "other"
I've heard factory resetting might or might not help
I've also heard of something called "iPhonecleaner" a program I can download on my computer and clean my phone with, I don't trust it though.

Not sure about any of this
I just want some data back at least 3-5 gigabytes free
No reason it should say I used 10 gigs

So help?
Please
I can't live on 1.4GBs!

What the best ios version for iPhone 4S?

My favourite to worst
1. Ios 6
2. Ios 5
3. Ios 7
4. Ios 8
5. Ios 9

I favourite is ios 6 because it was the best and last version Steve job make and I got ios 6 back from shitty ios 8.3 now apple **** up ios 9 big time ios 8 and 9 sucks but ios 7 looks ok

Overloaded iPhone 4S still fixable?

My friend plugged a 12V RC car charger into the audio jack of an iPhone 4S. The plug sparked then the screen went to all sorts of colors then turned to red and finally black.

Is this problem still fixable?