Hola V1... When I saw this post I just knew that I would find you here!
After some South Sudan time I can only back up what V1 says.
The book was written in order for you to operate the aircraft safely and efficiently.
As far as take off's we have the speeds for the appropriate weights from the AFM and those are flown
knowing pilots...one can say sometimes
Landings in the Twotter are some of the more interesting aspects of flying this able aircraft.
The runway surface/length will dictate the flaps used for landings. I don't recall flaps 30 being a normal landing flap, usually it is either 20 or 37.5 as per the AFM. The caution with 37.5 is directional control AFTER you get it on the ground
I have been presented twice with crosswinds that were such that I could not land with full flaps, just couldn't get it on the ground
Option A was a long runway so an eventual landing/arrival was made with Flaps 10 and a strange angle on the horizon
Option B cannot be talked about here otherwise V1 will be visiting me sooner than I expect him
Suffice to say droping over the trees into 400m with a strong croswind will probably require some clothing changes
the first time you do it but if you manage it the first cold one at base is going to taste real good
Happy flying in this unique member of the dehavilland family