Mid week should be quiet , Walk on , max 20 min queues, except Smiler as it's new.
Most people tend till wait till mid Oct for Scarefest to start.
Weekends much the same , we went on the first Saturday of Scarfest last year and we had ERT as we are pass holders , Managed 4 rides on nemesis and a snack break before the park opened and then did Air twice as soon as it hit 10am so we beat most of the queues.
Water rides will be dead as it's colder but we take water proofs and max the rides on them.
Rita Always has a queue, don't be tempted by the single rider queue , it hardly moves normal queue should be fine , it has a slow throughput so might be best left till the end of the day .
Towers will be closed to set up the Scare mazes ,( but not many people go for the history) Hex still open but generally will use and alternate exit.
Sorry for the essay
Bit of a Alton geek , if you need anymore advice try Towersstreet.com . It's a great forum for Alton and other Merlin Parks , so they may help with Drayton too
Vicky