I've also noticed the ghost touches on the 4, I don't think it's fixed entirely. Quite often have to physically put down the phone on a table to be able to press a button on the screen because I think it's somehow picking up my palm even when it's not touching the glass at all
I tried taking the whole charging port out and going at it with a little brush, no improvement.
As I use my phone as my primary means of payment I've unfortunately just had to shell out £20 for a new one which I am not happy about (postage, VAT, other bullshit)
Personally I've been using outlook via pwa for months anyway
If they're gonna put it in an electron container anyway you be may as well cut out the middleman and just use the web app Microsoft's ones are actually quite good now
You could ponder the meaning of life, the universe and everything