Minecraft commands help

When using selectors, all of the arguments go between the same pair of square brackets and are separated by commas. What you wanted to do is probably this:

testfor @e[type=PrimedTnt,x=-272,y=58,z=-1844]

You're getting the error message because you've made [x=-272 y=58 z=-1844] an argument of its own, not part of the selector. As it happens, the second argument for testfor is NBT data. The correct syntax to specify NBT data would, as the answer above says, be {x:-272,y:58,z:-1844}.

HOWEVER no entity has an "x" int, a "y" int, and a "z" int in it's data. Although it's the correct syntax and won't cause an error, it will never match an entity. The correct tags for specifying location with the NBT argument would be this:

testfor @e[type=PrimedTnt] {Pos:[-271.5,58.5,-1843.5]}

The chances are you didn't want to do that though, as it'd test only for that very specific point in space and nothing else. The solution is the first command I gave, where all of the arguments are in the square brackets.

There's a couple of problems with your command, but before we get to the problems, let's see the solution:

/blockdata -332 56 869 {Items:[{id:minecraft:clock,Count:1,Slot:12,tag:{display:{Name:"Time > Limit"}}},{id:minecraft:nether_star,Count:1,Slot:10,tag:{display:{Name:"Smash > Crystal"}}}]}

First thing to notice is that I'm using the item names instead of the ID numbers. This is required in 1.9, and works in 1.8, so it's what you should use. The second thing to notice is that I'm not numbering the list items, since it isn't really necessary. Instead of potentially screwing it up, just leave them out. The third thing, and what was really causing your problems, was that you were closing the list after the first item. Notice that you have ],[ between your two items. You need to just have the comma instead.