Well, I am less sure it will get much better than this.
Regarding the full application procedure, it could be demanded by external factors like insurances, pension fund, etc.
Regarding the seniority KLM will have to talk with VNV. This would add another item to the long list of KLM wishes/things to be 'solved' with the VNV.
I indeed doubt that the tax dept will agree on the 30% tax, because the change of contract is on your own request. Also this would add another item to the long list of KLM wishes/things to be 'solved' but now ofcourse with the tax dept.
All guess-work ofcourse and I hope things will be better.