Call volume shouldn't really be low. That's something that nobody complains about, so are you sure that the ROM is installed correctly? If you open up ViPER4Android it should allow you to change some options. If it gives you an error though then the ROM wasn't fully installed correctly.
You should find that if you reinstall the stock ROM that the volume level will be exactly the same.
Edit: This may be a silly suggestion, but you have tried increasing the volume while in a call, right? And you're sure that the person who's calling you isn't simply being quiet?
It's tricky to do. You have to handle the changes made to the libs folder, set correct permissions etc. You also need to restore data to the data partition and get all of the permissions there correct too. If they're not set correct then they can cause force closes or settings to not save correctly.
Probably not. I'll release refreshed builds with updated apps every now and then, but other than that there's nothing to really fix.
I got a new phone a while back so I've not even turned on my Y300 in a long time now.
If you're downloading directly from your phone then install AdAway and then disable adblocking. It should allow you to click on the link. If you're doing it from a PC though then something will be blocking it.
Open up Xposed Installer, click framework and select to uninstall. Then uninstall GravityBox.
If you open up SuperSU and go to it's settings you'll then see the option to fully unroot the device.
If you're going to sell the phone with a custom ROM then you should probably ask the person you sell it to if they would like it rooted.
Like xxirioxx said, even with HWA you can't play high def movies. The GPU simply can't handle it and there's not enough RAM. The Y300/G510 can only play standard definition video (360p and 480p if you're lucky). You'll have this problem no matter what ROM you use.
You could download GAPPS for 4.1.x and look at what libs are included. Remove them and then open up GooglePlayServices.apk and remove the libs listed there too. You can then also remove the correct APK's so that you're totally GAPPS free.
Keep in mind that when you remove GAPPS it'll break push notifications.
If you install the above GAPPS version over the stock version then it'll probably cause issues, so only use the files as a reference.
It's not possible to do a real backport unfortunately as there's way too many changes between the Android versions. The menu can only be faked, but it impacts the performance of the phone and doesn't function like 4.2 really does.
That's just the stock Huawei camera, which actually isn't any better. They both use exactly the same config to generate the pictures.
The size difference is due to the Google cameras gallery app having more effects and it doesn't tie into the OS the same as the Huawei version does. And although unrelated to it's size, it also doesn't abuse permissions like the Huawei camera does.
I've been providing the Huawei camera as a standalone app that people can install for a while now. The difference is that the version I supply is for B209 where as the version you linked to is for B199.
Yeah, the error itself is just hard to pin point. There's not a lot of info on it so you need to find similar devices that have had the same problem or keep guessing and trying different things until it stops doing it.
Fonz is doing well to support people here. He's pretty much the only dev that's actually bringing new ROM's to the Y300/G510 and fixing the bugs. He's done some really good work.
It's hard to say what would cause the graphical glitches. It could be highendgfx, but in general the forced mode does have issues of it's own. It helps to make the notification menu dropdown animation smoother, but it screws up with animated wallpapers. It's possible that the SwipeBack Xposed module causes a similar glitch.
ES File Explorer does the same thing for free. When you enable root within the app you just click on the text saying "Root Explorer" and then you'll see "Mount R/W" which will allow you to change the /system partition to RW.
As for deleting widgets, that's not possible. Most of them are built into apps and there's no way to hide specific ones.
With the beta version of Nova Launcher you don't even have the widgets menu. It's been moved to a new screen.
When you select to go back (the back button) it'll ask if you want to save the changes. If you correctly gave the /system partition write access then it'll save just fine and all you'll need to do is reboot.