In the ACARS stream we have three messages relating to the window deicing system, two that relate to smoke, leaving two that relate to other systems. In my career I saw lots of messed up computer transmissions, but these messages have a logical coherence. I'm not saying it is not possible that the messages are bogus, but there are a whole lot of ACARS messages possible for the computer to pick randomly from.
All of the messages make sense and point to some sort of fault either in the wiring at the business end of the right window deicing system (which has happened before) or in the inverter that supplies that power. If it is really 3kw @ 200 (205?) V then that is 16 amps of current wired next to a surface that flexes, vibrates, and drips water. Obviously it is extremely well engineered or this would happen all the time but past experience shows that there is a way to get to a smoky fire from this equipment.
There is not enough data of course for this to even be considered an explanation, but so far I have seen nothing that would falsifiy the scenario of a fire caused by a fault somewhere in the window deicing system. On the other hand, the lack of a warning about loss of cabin pressure when the ACARS system is otherwise still working does a fair bit to falsifiy the explosion scenario.
Of course, if one starts with the conclusion that it was terrorism you can always come up with some scenario to fit the data after the fact.