In first place, you can add any directory for spectrum tapes or disk. For doing that, select the spectrum system you want to play in the list, right click, properties, software tab, insert (Add the path to your game folder). All the games should be liste in the software area section, but not in the avaliable field (only for roms)
Second, you can change the scroll lock key in the internal ui, Input(general), User interface, Toggle UI.
Finaly for loading dsk files, use zx spectrum +3, select loader and intro with the disk in the slot, the game will load automatically.