Lolipop 5.0 can be downgraded to 4.4.4?

Only if you root your phone and flash a ROM based off a previous Android version. It's not possible via 'stock' options.
 
No reason to root the ROM that's in the phone if the next thing you're going to do is replace it with another (non-rooted) ROM. It's just a waste of time. Just back up everything (see Backing up an Android Device), then flash a 4.4.4 ROM, then restore everything.