Booking strategy & VA vs Qatar coded flight

[Wheretonext]

Hi I am hoping for some advice on the best strategy to book an upcoming flight with Velocity J class from Europe. I want to book them as soon as they are released and I have noticed that the ideal flight itinerary with VA8 is released a couple of days later than the other flight itinerary using Qatar flights (due to the flight leaving at 145am). Also noticed that the taxes for the Qatar version is around $60 more expensive. The Qatar version leaves IST at 1:30pm and arrives at MEL 4:50pm while I believe the ideal version is the one that leaves at 8:05pm and arrives in MEL 10:10pm (as it gives us a full day in IST to explore as our time is limited there)

My questions are:
1) Does Velocity let you change or cancel within 24 hours for no fee like Qantas?
2) If so, is the best strategy to book 2 J tickets for the non ideal flight times and change them to the VA flight version within 24 hours when they are released?
3) If the above strategy won't work, any suggestions on what is a good strategy? is it very risky to wait? I have noticed flights from IST to MEL are available in business for most of end of April so it seems they don't disappear immediately
4) Are there any differences at all in the offering under the VA flight compared to Qatar flights?

Thanks

 

[Wheretonext]

I have managed to find a few answers to my questions
1) there is only a 2 hour time frame to change a flight without a fee
2) not possible due to above
3) seems 4 seats are released on VA flight and 2 on QR flights so might be worth the risk to wait
4) not sure of this one yet