I mean, then I guess you should panic about the questionable defense getting better of the stacked offense.
Note I didn't say the offense can't or won't be good, just that it has more questions and requires more projection. QB is still young and was situationally terrible on critical downs and in the second half. RB losses are frankly irreplaceable and in many games Texas only had a functional running game because of those guys. OL is going to be a significantly better run blocking unit on the interior to mitigate that (Campbell hopefully helps there but one man is not going to fix that problem), and the passing game is going to have to carry more of the overall offensive weight. Worthy was comically bad at times last year, Neyor is coming off an ACL, and Whittington's healthy season, while great to see, was an anomaly. AD Mitchell and the freshman class no doubt upgrade the pass catching talent overall and I expect Worthy to bounce back, but the ability to set those guys up for success is an open question.
As to the bolded, ??????
Sweat, Murphy, Collins, Broughton, Sorrell, Finkley, Ford, and Gbenda were all starters or in the rotation last year. Trill Carter wasn't but was an honorable mention all Big Ten selection last year and three year starter at Minnesota. I'll take my chances on replacing Ovie full time. As you pointed out the edge play left plenty to be desired last year, especially outside of Sorrell, and the overall defense was still strong. Overshown is a bona fide loss and that second LB spot is shaky but Anthony Hill projects nicely to filling a similar role; though it's worth noting that as a pure LB Overshown was far from elite.