One would expect that such things on main components would be found in the design phases, with all the great design software we now have around.
These fixes look strange:
Oops, titanium too heavy:
Fix: chuck in aluminium spar
Oops, not strong enough
Fix 1: machine it a bit
Fix 2: re-desgin it to dilude stress
It does come across as fixes with no thought-through planning of consequences.
All the other stuff sounds like engineering quests.