Seloco, since (obviously) different aircraft have different equipment of varying ages and sophistication, it is not really possible to have a common standard. Older radio equipment is rather more susceptible to interference, but more modern does not necessarily mean better in this regard, since higher-tech equipment such as Slasher's moving map display are fairly vital to navigation, and my aircraft doesn't even have one.
I must admit that I am surprised that some airlines allow passengers to use mobile phones after boarding, since this could upset INS position initialisation, which usually is accomplished by a DME/DME fix, or VOR/DME or whatever the best fix it can get is. Much equipment, however, you can simply enter an airport and a stand number and it then knows from its internal database where it is.
I agree that a note, say, on the Safety Briefing Card might be a good idea. It would need, of course, to be displayed in pictogram form to save language difficulties. but I'm sure that is not insuperable.
I'm not particularly surprised at your recent "best" problem trying to use a laptop. It is quite possible that there was some minor unserviceability with the aircraft equipment that does not stop the aircraft flying, but does mean that unusual extra rules have to be imposed. It doesn't necessarily mean that the airline staff were just being stupid, difficult and unreasonable!
If you've seen the movie n times (where n is a large, positive integer) before, then how about reading a book, or listening to one of the aircraft's IFE channels?
As far as "unpleasantness" is concerned, I would be very worried if the approach from the cabin crew was anything less than polite and friendly. If not, then a letter to the airline might be in order. If, however, the response the crew gets is less than they would like - in other words, switching off the offending article, then things are going to start getting slightly warmer...
Put simply, if the crew tell a passenger to do something for the safety of the aircraft, and he refuses, then the consequences are not going to be pleasant for anybody.