Q1. Does NWK_ACK works without enabled NWK_ENABLE_ROUTING?
Yes, it does. But you still will be able to communicate only with devices within the range, obviously. But they should acknowledge the received frames.
Q2. Does NWK_ACK works without enabled #define NWK_ENABLE_ROUTE_DISCOVERY?
Absolutely.
Q3. Where I should get information about: NWK_NO_ACK_STATUS?
void appDataConf(NWK_DataReq_t *req)
is the right place?
That would be the only place.
Q4. When NWK_NO_ACK_STATUS information is available?
At the moment this function is called. And it will be called after ACK wait time if no ack is received.
Q5: Which program events call
void appDataConf(NWK_DataReq_t *req)"
?
It is called only in response to NWK_DataReq(). If there is no pending response, then this is just another function. It has no special meaning, it takes the meaning as a request callback when you specify it as a parameter of the request.