It was only the older models that had the engine driven hydrolic pump. It was later changed to the electric model. POH for your specific aircraft will tell you whats what. (heres a hint. If all the knobs and handles are huge and white, the pump is a engine driven type)
Thos gear doors and sidways wheels are worth ten knots when selected. if teh gear is down, leave it there until you can afford the loss of performance.
keep a close eye on the temps on the back engine, as they regularly run far hotter rhan the front one.
As
TQ said, lead your take off with the rear engine, then the front. a partial loss of power is very difficult to detect until you can afford to pull a throttle to check which engine your losing.
TQ, hehehe, I remember the castor wheel comment.
also remember the guy that was instructing had to endure another gear retraction in a Mooney shortly afterwards.