Sadly to tell you, no.  ,but might have in the future.

Data sense is coming in the next update, known as Amber. But not sure will Malaysia will support a not. 
Do not press back or lock the screen. Just stay at the download page and stare at the bar. 
EDIT, still waiting for 925 to reach shore so can confirm whether there's data sense in it or not since it seems to depends on carrier.

I can still download video with my Youtube apps       

Lots of catching up to do for MSFT, although they doesnt seems to care. 
If not for Nokia, i wont be using wp8 phone. But since nokia choose wp8, i got no choice but to use it.

If you put it this way while stop comparing with any competitors.

- amount of time poured into making and research on the OIS.
- same goes to 41mp
- high quality mic that's been exclusive to Nokia (hTC One also shares the same tech)
- best communication technologies from Nokia (We're talking since 3310  )
- Global navigation license for the package (Almost the whole world, offline too)
- EXCLUSIVE apps suite 
- Unique design since N9.
- 10,000 patern portfolio from Nokia. (Apple and Blackberry is paying, maybe hTC soon)
10,000 Strong: Nokia’s Patent Portfolio Is One Key Advantage You Forgot About

Competitors merely bump up the specs and revamped the UI and offer you at flagship price.

Just my POV yeah. 

Samsung caught cheating in benchmarks with the Galaxy S4
this really make my day... now we know why android lags... cause their fav scamsung cheats on benchmarks... lol... in your face scamsung... gotta love no lag WP8...

100% charged, ON WiFi from 7AM to 7 PM and the battery is single digit already.

Is that normal?

USB, nope, not yet for now.
Tag, it is better to post a photo from the photo album. Open the photo, share it and select Facebook, and you add tags from there by typing out their name and selecting them from your FB contacts inside People's hub.

can android & ios fb do this?

The only thing I really really like about the Facebook app on Android is the Facebook Messenger which pops out a bubble head for your contact, while doing your readings on your device you can chat with the person without pausing the reading app, pretty neat.

The downside of the Facebook app on Android is the noticeable battery drain as proven by the folks at XDA, to fix it simply logoff Facebook when not in use.

lumia 920 la brader.. With proshot,p mode, no flash, ev set to -2/3, daylight wb, it is my default settings to be honest.