Comprehensive Veterans Benefits Improvements Act of 2007 - Makes various changes or additions to veterans' compensation, pension, health care, housing, burial, and other benefits, including: (1) a report on veterans who were misclassified as not being catastrophically disabled; (2) a pilot program on veterans' lung cancer screening; (3) a repeal of the prohibition against the concurrent receipt of veterans' disability compensation or pension and military retired pay; (4) an increase in the rates of veterans' disability compensation; (5) a repeal of the reduction of Survivor Benefit Plan (SBP) annuities by the amount of veterans' dependency and indemnity compensation (DIC) received; (6) a report on the adequacy of DIC for survivors of veterans who die from service-connected disabilities; (7) a reduction in premiums under the service-disabled veterans life insurance program; (8) an increase in the veterans' burial plot allowance; (9) an FY2008 authorization of appropriations for the state cemetery grants program; (10) an increase in grant amounts for specially adapted housing for veterans; (11) an increased coverage amount under the veterans' mortgage life insurance program; (12) adjusted veterans' home loan fees; (13) judicial review of the adoption or revision of veterans' disability ratings; (14) establishment of the DOD/VA Clinical Information Data Exchange Bureau; (15) a study and report concerning the disability ratings systems of the Department of Defense (DOD) and the Department of Veterans Affairs (VA); and (16) a report on the provision of assisted living benefits for veterans.