You can have two different Xbox LIVE accounts on the same Xbox 360 for sure. I've had 4-5 on mine at one time between roommates and such.
You can also recover your Xbox LIVE Gamertag to any console at any point. Your account can only be "active and updated" on a SINGLE console at a time. (What this means is that it must be recovered to a console before you can use online services on it. This makes it so more than one person can't access your account at once.)
The way that purchasing marketplace items works is this:
Whenever you buy any item on the marketplace, it is tied to both your gamertag and your console. Let me give you an example.
Your gamertag is PersonA and your friend's gamertag is PersonB. Let's also say you have a buddy named PersonC who is visiting and has his Xbox LIVE account on a thumb drive.
Your Xbox 360 will be XboxA and each respective person's Xbox will be XboxB and XboxC.
Following along?
You buy an Arcade game on XboxA as PersonA. This means that ANY PERSON (A,B,C,etc.) can play this game on XboxA (YOUR Xbox), OR you can download this game to play it on XboxB or XboxC on your account only.
Make sense?
To summarize--when you purchase the game as PersonB on XboxC (just a random example), either PersonB can play it on any Xbox, or any person can play it on XboxC.
If this doesn't make sense I can clarify further.
Hope it helps! Happy gaming. :)
Edit: I wanted to add a tip. Say you and a buddy both own Halo: Reach and you want some new DLC for 800 MSP, right? Well, if one of you knows you will always be using the game on your own name on your Xbox and no one else will be, you can buy it on his Xbox. That way, anyone on his xbox can play it (him) and you can play it anywhere (on your own Xbox).
It's not illegal or cheating the system or anything, since the permissions are still restricted as such.
Kinect only saves your facial recognition data in its numerical form and only locally. Since the data is not sent to the cloud you won't be able to just sign into your account on a friends console. Here's a snippet from the Kinect Privacy website:
Data Used for Sign-In. As an optional feature, Kinect can collect and use identity data to enable you to sign in to your gamer profile. This is mostly facial recognition data that identifies individual players. You can decide whether to use this feature, called Kinect ID, and control whether this data is collected. This data is stored permanently on your console to enable sign in to your gamer profile, and is not returned to Microsoft. This information is stored as a long series of numbers, and it does not personally identify you.
Copying your profile however could work since it will take the local data associated with your account but I don't have a Kinect to confirm it :( Sorry. For more information you could check out the link
Source: Kinect Privacy and Online Safety
Hope that helps :)
Best Answer
The Xbox One is region-free but only for physical copies of games. If you want to purchase content online then you need to have a US bank account, as Ghana is not a supported country. I have an Xbox One S - NTSC and I redeemed the Minecraft code that I got. I can assure you that there will be no problem faced while redeeming the code.