Thanks for the welcome, very good forum, I must say
Settings -> Storage gives me a list, but it is unclickable - i cannot access any sections, only different colour labes and titles I can see.
Well, it is my first smartphone (been using old old nokia) - and it is AMAZING. I did all the research and played with other models, but this is the ONE. Im sure the GS4 is just as smart, the one just fits my needs perfectly. What really blows my mind is, when i was 14 and bought my first 133 mHz pc it cost $1600 - now I got a quadcore 1.7 gHz for 1/3 of the price - and it freaking fits in a POCKET. Right now I feel like im in love!
Unfortunately the "other" category is pretty broad and my understanding is that it includes the OS, cache files, game data, possibly Google Music that is pinned to the device and other things. So it could be very user-specific on how much this should be taking up, depending on what apps you have and what you use your phone for.
I know that's not much help, but might be worth evaluating what you might have that could be using that space.
Welcome to Android Central! Try going to Settings/Apps/All, and see if you can sort by size (tap the menu button when you're on the screen). Then see if there are any apps that are taking up an inordinate amount of memory. You can then tap on the app to see if a lot of the memory taken up is cache, which can be cleared. Might be worth trying App Cache Cleaner to see if this can temporarily free up space.
As to your question about the proper way to hold the smartphone--it's totally up to you. As long as you don't have an iPhone 4, any natural way of holding your phone won't affect reception. Most phones can have decreased reception if you hold them with a so-called "death grip" (i.e., holding it tightly and covering a lot of the phone back, typically with 2 hands), but in reality, no one really holds a phone like that. How to hold it while typing depends on the keyboard that you use. If you prefer a keyboard that you tap, then landscape might be easier, so that the keys are bigger and easier to hit with your thumbs. If you prefer a gesture keyboard like Swype or Swiftkey, it's probably easier to hold it in portrait orientation, so there's less distance to cover when dragging your thumb or finger over the keys. For taking pictures or videos, just make sure your finger doesn't block the lens.
I too am an ONE user and as I can see in my phone, I have arpx 13 gigs free. Of which the break up is of Other is 7.91
I believe Other includes OS, Cache, repository etc.
And as far as I know, JB 4.2 and HTC Sense might make up more than couple of Gigs together. So it is perfectly fine to have that much memory unusable