It is strange because I am not feeling any of what you are saying in my play. I don’t fly out of combat much and if I do it is a short dash low to the ground to keep myself hidden. I agree he is the slowest monster thanks to his slow traversal ability compared to Goliath and Wraith.
I have actually found that leaving banshee mines behind every wall and cave entrance I go past slows the hunters down a lot, also often leaving them on low health if they are not really on the ball. I have killed many teams at stage one thanks to banshee mines, I get domed and just kill everyone, each person who is down gets a banshee mine on their face to keep allies from trying to rez them, anyone more persistent is hit with vortex or lightning strike and that usually results in another down. If this doesn’t wipe the team they usually have enough strikes for me to close out the game at level 2.
I also find that in combat I keep enough distance and stay high in the air so that the enemy can rarely break through my armour, often just running out of jetpack constantly trying to get to me making them easy targets for lightning strike.
If it helps, my build is Level 1, Banshee, lightning, vortex, one point each. This is the kite kit. If people chase you throw vortex and lay banshee mine traps. Level 2, max lightning and add another point to banshee(edit: It occurs to me I don’t always add the point to banshee, sometimes I add it to vortex instead depending on if I find my mines are actually doing damage/enemy team shoot them consistently), continue kiting, if you get some one down or see some one who could be lightning one hit, try it and you will usually win, if you miss, keep kiting.
If for some reason it gets to 3, I finish vortex and 1 point in aftershock, or if I have enough strikes to be aggressive or need to throw a curve ball at the enemy, max aftershock.
With this build I have NEVER lost as kraken, either in the big alpha or in the current beta. Good luck!