Like I said, get a small suitcase for hand luggage with wheels, and a laptop bag which you can slip over the hand luggage handle. I travel like that everytime. You can still run with it all if you need to and because its on wheels you dont kill yourself lugging it around the airport.
In regards checked in luggage. When we moved here I padlocked all our suitcases and everything arrived safely, even the playstation 3 I had in one suitcase. Also had a 32" TV in its original box, and surrounded it with clothes and taped it up, no problem. But another time we came via Madrid and forgot to lock a suitcase and it arrived minus some new(ish) Nike trainers. I`ve also gone back and forth several times and brought many electricals back that were too big for handluggage in the suitcase without issue, just always padlocked. Way I look at is, if its replaceable and not worth too much money put it in your suitcase. If its difficult to replace , expensive and small enough, hand luggage.
Also, They did scan and check everything when we came through customs originally, even had to open the TV box. but because we were foreigners moving they were only interested in illegal items, nothing for personal use.