> but is it normaly that u can only hack 15 items?...
There is no limit in general. There are currently over 50 DLC items but there are only 15 pocket slots (ie. your inventory).
When using EZ_DLC_Install it has a feature to fill your pockets with the first DLC items. This is less useful now with so many new items.
For placing more items, use ACToolkit *after* EZ_DLC_Install. You can pick which items you have in your pockets, or place the DLC items in your house or on the world map.