You mean settings --> System Updates?
For me it doesn;t show to much either, a line at the top showing 'System updates' and 'already running latest 4.8.8'. And a single button at the bottom showing 'check updates'. But for you it shows nothing?
Have you tried a factory reset? (Settings --> Backup & Reset).
About recovery mode, strange that it doesn't work.
Have you tried shutting it down completely and press volume up and power button to turn it on, release the power button once you see the 'miui' boot logo but keeping volume up pressed all the time until booted into recovery?
Recovery only works with an 'update.zip' file in the root directory of the internal sd, so you'd need to rename any downloaded roms to update.zip...