You listed a bunch of stuff but failed to mention checking for spark at the plugs. Also you need to losen a fuel line in eng. compartment to check for actual fuel flow - just losen a clamp and have someone turn key on (not start) make sure you have fuel pressure. That sputtering sounds like a fuel issue (IMO)..
I'll try to think of more when my head is on straight - (been up for 41 hours, shitty food, shitty surroundings and weather here in UK sucks balls)