What and how do I uninstall unwanted apps?

Hello,

I just bought a Galaxy Tab S and I was wondering if there is any way to remove some of the non-essential apps. My RAM is at 1.87 out of 2.7, and I want to free up as much as I can. I don't really know what apps I need for the tablet to run, but all I will be doing on it is watching and streaming movies and streaming my PC games via Gamestream. Which actually brings me to another question: Can I use my Dualshock 4 controller with Moonlight Game Streaming or do I have to purchase an OTG adapter?

Thank you in advance for your help.

Looking for install logs / unwanted app keeps getting reinstalled

Hi!

I recently got an android 4.4.2 phone ( "uhappy up920" ) and I can't find any logs or any way to see WTF is going on. An application that wasn't originally included ( "Maxthon Cloud Browser" ) keeps getting reinstalled and I can't figure out how / why.

( Phone isn't / probably can't be rooted )

Any hints?

unwanted lock screen appeared. help?

several weeks ago a new lock screen appeared - out of nowhere - and now won't go away. I've tried to manually go into setting and change it - no luck. When I restart my s5, my original screen (which is still selected in settings) comes up, but is then taken over by this lock screen that won't go away. I'm running Themer - thought it was associated with that, but I've since cleared cache/data/deleted it, with no luck. This thing doesn't keep time, give any notifications, or swipe responsively. A real PIA. It also affects the notification bar - won't give me my notifications. Same with the lock screen - occasionally I will swipe my screen and see the original notification bar, but mostly this new one. Any thoughts? I'm really not keen on wiping the whole thing are starting from scratch.