I am currently looking to install Ubuntu on my nexus 4. I have checked the site and it is on the approve list of devices that can support the software. Are there any risk in changing the software type on my phone? Can it have any effect on the hardware?
Installation of ubuntu on nexus 4 risks
You can install Ubuntu in your nexus 4 device but remember this is a preview version and this is not intended for regular user. Ubuntu has released this preview for the developers to test and contribute on it. If you want to test with this dual boot installation you can install it on your Nexus 4 device. But you must be familiar with the Ubuntu and Android partition layout. If you see something wrong after installing you need to flash the partition manually. As it is in development stage so there may be effect on your software or hardware after installing Ubuntu. If you are not a developer, you should wait for the final release.
If you install Ubuntu in your Nexus 4 you will be able to run Ubuntu and Android on a single device. On android two application need to be installed. One is Ubuntu installer app and another is boot into Ubuntu. Super user permission is required to install these two applications. On Ubuntu, a single dual boot application needs to be installed to boot into Android.