My knowledge of UK law is limited, but what strikes me as odd is that he's facing additional punishment for several actions that aren't themselves malicious. It's not just a single charge for aiding in a terrorist attack, but a whole range of separate charges (with heavy punishments) for possibly related but otherwise completely innocent actions.

But those other actions only appear to be a crime if meant to aid terrorism. Or am I wrong?

see eg CA: possession of lockpicks is legal. If you have criminal intent, which must be proven, possession is a felony.

I don't really think that particular law makes any more sense.

If an act is only a crime when used to prepare for a more serious crime, then the crime should be 'preparing <serious crime>' not the preparatory act. If an act can be shown to be preparation for a more serious act then the person should be punished for preparing the more serious crime (which usually has a maximal punishment equal to actually committing the crime), if there isn't enough evidence to show that the preparatory acts shouldn't be punishable either.

It really seems like a way to try to convict someone with shoddy evidence, or some roundabout way of trying to get around double jeopardy, or perhaps to criminalize intent, rather than acts.