Alright, so going back to my original topic, are there any apks for the prime that u can use and don't need to be rooted?
The short answer is no.
The longer answer is there are two version of the keyboard floating around out there, one is flashable and requires a custom recovery (which requires unlocking) and the other just needs to be dumped into system/app along with a handful of support lib files, but that requires root which you need to be unlocked to get.
Both approaches do the same thing, the flashable one is just more automated and maybe a bit eaiser depending on your perspective.
Now, just to hijack your OG topic a little more, sorry
Rooting on this device it's self won't void your warranty. It's the unlock process which requires you to basically tell ASUS you are unlocking before you can. It also displays a message on boot that says "This device is unlocked" or something to that effect. Now, that doesn't mean anything. Unlocking CAN void your warranty if ASUS decides to enforce that policy. Usually it depends on the problem you are having.
The bottom line with unlocking is that it's a calculated risk. If you read and do your homework the risk is pretty minimal and there are plenty of resources out there to get you moving. I've been unlocked since about day one and I've been fine. I get none of the lag or stalling you see sometimes while on stock which is really the only reason I went the custom ROM route on this device. I get no slow down or lags at all.
Now that being said, there's a real fear with this device and if you do something wrong you CAN brick it. There are 3 ways to brick it, 2 are soft bricks (recoverable with some work) and 1 is a hard brick you can't recover from yet unless you have an NVFlash from before the JB update. Once that comes out for the latest version though the device is virtually unbrickable.
So yeah if you care enough and want to do your homework, it's not that hard but for most people they won't have any interest and that's fine.
EDIT: adding to that...Swype and Swiftkey are better anyway in my opinion so I would just use those.