Question [Q] i9505: WiFi not saving key, invalid IP address

My GT-i9505 has a problem with the Wifi. I bought it a month ago and the Wifi stopped switching on after 2 weeks suddenly, no idea what caused it. I formatted the phone and that fixed the problem, it's been working fine since then. Now I have 3 more small problems all related to the Wifi:

1) It takes a while for Wifi to switch on now, maybe 10-15 seconds. It seems to get worse every time I leave a place using Wifi by letting it disconnect on it's own when I go out of range.

2) I have to input my WPA key every time I connect to the same home wifi router (Dynalink RTA-1025w). How do I get it to save my key/password?

3) It almost always connects to the router without being assigned a proper IP. On DHCP it usually assigns 192.168.1.3 when it works, but sometimes it says ::1 instead. I have to change DHCP to Static and manually input 192.168.1.3 and that fixes it instantly, but I need to do this and input my WPA key almost every day.

I was planning on rooting and installing CM but I thought I should ask about my wifi problem first. I'm assuming CM will fix these problems but I thought I should double check and ask whether I should fix this before installing CM, just in case I make the problem worse. This is also my first smartphone so I'm completely new to all this (my last phone was an old Nokia E55).


Another unrelated question. What's the difference between the CM on cyanogenmod.org VS. KVT49L [AOSP] 【4.4.2】Dan&Ktoonsez 【CM Edition】on this forum? (http://forum.xda-developers.com/show....php?t=2763735)
I'm guessing the latter is the same thing but with further tweaks, fixes and additions, correct? I would ask in the relevant thread but I don't have permission. As a legit newbie, I'm quite overwhelmed with all the CM choices, how do I know which is the right one for me?