All the undesirable traits you mentioned in your post, "the lack of the will
to fly, flying a just bit off the kit, nervousness during night fly, lack of
obedience, raking for too long, not trapping in time, dropping on its own"
are not undesirable traits but are just the breeders fault who didn't train
his birds to the standard a tippler should be trained.
Advice should come from Mike and Nino and a few others that have flown well
in contests. I'll give you my advice for what it is worth even though I have
much the same problem as you do.
In my opinion, your tipplers are being fed possibly too much of the better
grains, etc. Maybe more malted barley in the diet, about 60% or more
depending on how they react to that amount in the mix.
Is it the gene makeup of a bird to fly long hrs, or does training and proper
management have more to do with ones success? I believe the bird first must
be genitally infused for endurance flight, but that proper training and
management is the bigger key!
For me the birds have to be sound and if they are then it's all management,
no contest. The reason I say this is because I have seen it time and again
good birds end up being bad, all fault of the trainer. Even though there are
mountains of information on training and feeding some still try ass backward
methods accompanied by fast track short cuts......never works.