Temporarily disable attack and move

I'm scripting a spell that needs the caster to forget about attacking or moving until it's played out. Is there any way to do this without pausing the unit? (I've had problems with this, hero ended up in an infinate spell-casting loop.)

Use 'Channel' as the ability base and set it to disable all other abilities. I think that is what you want.

If I can use it to target a single unit...

You can. Channel is a godsend for triggerised abilities.

Just set it to Targetable.