UIUC, UCSD, and Purdue should be moved to the reach category for CS. Be aware that they may admit to the school but not the CS major (i.e. admit either as general undeclared or to an alternate major), in which case changing into the CS major after enrolling will be very difficult.
Regarding UCSC graduation rates, the 4 and 6 year graduation rates (overall) were:
entering 2015: 62.3% in 4 years
entering 2013: 53.3% in 4 years, 77.1% in 6 years
As expected, non-Pell, non-first-generation-to-college, and female rates are higher.
https://www.universityofcalifornia.edu/infocenter/ug-outcomes