1000Kv Motors on 500cm frame and 2kg's of Drone?

Hi guys. As I have calculated on ECalc(A drone performance calculator program) with 4 1000kv 28 series motors, 4S LiPo (1600mah 55/80c) and 2kg’s of drone I have like 2.5 TWR. I’m trying to build a very stable and fast but not so efficient drone. Is 2.5 TWR A bit too much?

No, it is not.
It is always a good idea to design multi-copter vehicles with a thrust to weight ratio >= 2.0

Will increasing it to like 3 TWR decrease stability