Answer the similar question about a minute ago. This set is tapered and if you look at the packaging closely it gives you a cross reference from the SAE set to what metric screw heads will accept. Therefore, you do not need to have both sets.
They didn't have one at this store, but you'll notice that the bid ends are tapered so they have a conversion chart and it's supposed to work with both metric and SAE. Hope this helps.
Didn'see one. They do make extensions if you need it longer. I'mean sure someone makes a bigger set. Try a specific search on the Internet LOL!
No, the tip set is not available in metric.