Seems pretty cut and dry for 1000 pt army with a Stompa. Doesn't leave you much room to play with points-wise. That's probably why you don't have much feedback.
List seems solid with the consideration of incorporating a Kustom Stompa. I played against a Stompa (Buzzgob's version) at a local
RTT and I maxed against it. I simply let the pie plates hit me, assault another squad, and stomp out of a combat a third, every turn for 5 turns. All while, maxing out on objectives and killing the rest of his army. That being said, I see your army only had Ten(10) 6+ Tankbustas, Seven(7) 4+ Warbikes and a 6+ Armour Save
HQ with 3 wounds. That's 20 wounds that die to Heaby Bolters or better with no invulns (not that Orks had any to begin with

)
If you're content on using the Stompa, just be prepared to play cat and house with your Obsec Bikes and avoid
LOS as much as possible. You're going to be close to being tabled (short of the stompa) every game and giving up free Slay the Warlord.
Good luck in your tourney!