The answer is yes, sort of. If you load the rom, it will appear in english on your device.
However, once you flash it, you should let it settle for a few minutes to build the caches and then reboot, just about everything will be in English then. Next,
-Change the Date/Time settings. It will be set to China's gmt
-Go into mylocation>gps configuration and change it to the correct server (e.g. for me from cn.pool.ntp.org to us.pool.ntp.org - from china to us).
Certain miui apps will be in Chinese no matter what you do. The uploader, downloader, Firewall, and monitor as well as MiTalk will be in Chinese. The Chinese market will be on there, in Chinese, and it will keep sending you notifications on the notification bar to update it.
As for translate it it english,
That is what Mark and the Devs here do for you so you don't have to. I suppose if you were interested in that you could contact Mark and ask him.
Hope that helps.