Yeah, that won't work. The offsets need to be set correctly (in hex) so the ROMs don't all overlap. Try this:
<rom name="t2_u14.l3" size="131072" crc="9addc9dc" sha1="847bb027f6b9167cbbaa13f1af50d61e0c69f01f" offset="0"/>
<rom name="t2_u15.l3" size="131072" crc="dad03ad1" sha1="7c200f9a6564d751e5aa9b1ba84363b221502770" offset="20000"/>
<rom name="t2_u18.l3" size="131072" crc="2280bdd0" sha1="ea94265cb8291ee427e0a2119d901ba1eb50d8ee" offset="40000"/>
default="1" is the song number that is selected by default.
cpu1 is which CPU for drivers with more than one CPU; pinball CVSD only has 1 so "cpu1" is the only valid option.