Clearly, there will not be enough room for all the blocks on that bar. Many have suggested shift+key or ctrl+key, but that would be annoying for blocks you use often. That would work fine for building mode, but it would only allow for 27 total slots in your inventory (or 36, if you included alt+key) in survival mode. Thus, my idea is that in the ESC menu, you should have an option to change which blocks/items go into which quickbar slot. Thus, the ones you use more often will be more readily acessible. The one drawback I see to this is that it seems that it would be rather complex to program.
Also, I suggest adding a tenth slot for the 0 key.