Applications backup (+ likely reinstall on new phone)

[BigBug]

Hi:

I have a Nexus 5 (with 32G) which I got from Google Play store in March. It came with Kit Kat 4.4.2 and I have made upgrades to 4.4.4 (the phone is not rooted). I use T-Mobile. I only have a few third party apps on it.

I am pretty sure I have some bad memory (here is my thread on my issues). I am about to do a factory reset but before that want everything backed up. I use the usual Google backup which seems to have my contacts, calendar, and apps. I did a manual backup of my internal storage to my laptop. And did CallLogBackupRestore and SMSBackupRestore to get my call and text history.

I think what I am missing are some things within the apps. For example, I use kik and would like to backup my current conversations. I have no idea where this is located. I did see the programs Helium and Holo Backup. Would these backup conversations within kik?

Also in the likely event I have to RMA this phone to Google, are there any complications with reinstalling everything on a new phone (but same make and model)?

Thanks for any tips!!