The bug you found is Gapps related, you might want to contact Banks team to see with them, officially, OmniROM doesn't offer support for Gapps, we only tend to recommend Banks because it has been proven that it's working well without being bloated. But then, it's nothing official on that matter. Any device maintainer is actually free to do the recommendations he wants towards that device.
Maybe Ubermallow uses a different icon for Launcher3 (customization), and from what you're saying, they apparently ship velvet.apk with the ROM.
OmniROM is AOSP based, and we don't ship any proprietary/closed source app, Google Now Launcher is a proprietary Launcher made by Google.
I don't know why Banks don't shipp Google Now Launcher with velvet.apk, but OmniROM does not ship it.
Afaik, the only proprietary piece of software you can find in OmniROM for Nexus 4 are the drivers and libraries given by Google.
That's also one of the reason why Supersu isn't shipped with OmniROM, because the code is not open source.
I don't want to sound harsh here, but if you did read through the thread, and I think I said many times that Google Now launcher was not included with Banks gapps and needed to be installed separately.
I wish I could do more for all of you when flashing gapps, provide a bulletproof package, but I unfortunately can't do that, lack of free time, and user support would be way to important compared to what I can actually provide. Building OmniROM is still a hobby, time that I take on my free time, and no one at Omni is paid to do the job, we all do that out of passion for the OS and for the device we maintain.
I myself keep on providing at least a build per week until nightlies start, but I can only do this when I go home after work, and I still have a family I need to spend time with

That's why sometimes, I might omit to repeat things I already said in the thread, hoping users will eventually find their way to the answer they're looking for
If you have any question regarding the ROM itself, feel free to ask.
Hope you have fun with OmniROM !