On the 29th day of your trial period, open up the command prompt, and type this in:
Now reboot. That gives you another 30 days on your trial period, you can rearm a maximum of five times before you have to activate a license, or risk being locked out and having to reinstall Windows. "slmgr /dlv" lets you know how many rearms you have left.Code:slmgr -rearm
As for moving to Windows 8/8.1, that's entirely up to you. There are useability and some performance enhancements, but for games and your workload, 7 will continue to work just fine.
There are minor (1% or less) differences in performance, but they are down to the various versions of Windows running different services. Home Basic is the leanest and cheapest of all the consumer versions, but offers you very little customisation in return.
For gaming it's also very limited in terms of hardware support, because the 64-bit version is capped at 8GB of RAM. That's not an issue with the standard version of Windows 8, which goes up to 128GB. If Microsoft continues to give out major updates to the OS for free as with 8.1, it might be the better long-term choice.
Just use a local acccount instead of a Microsoft one.
Pretty much this is all one needs to think about. If you want to stay on the PC and experience games with every visual effect turned on (providing your hardware can support DX11.2) then it's the better choice. But I expect DX11 to now supercede DX9 and become the new baseline, considering how many new games are dropping XP support.
If you own a laptop and have switchable graphics AMD + Intel. Stay away for the moment. NO drivers at all. You have to get custom drivers such as leshcat which don't have windows 8.1 certified graphics driver at the moment.