Here's what AXI/Canonn have come up with so far...seems about right based on what I have encountered:
1. They do not always activate the Anti Guardian Field, most of the times it happens when they just spawn and u are within 10km range, but even this is not always 100% accurate
2. They have a weak spot to expose, likely near the engines but not confirmed there
3. It seems to have to turn and point at you to fire the missiles, which may explain it slowing when it fires a missile.
4. Glaive's missile speed is 650 m/s
5. Anti-FSD missile only fired when you are running away and has a rear aspect shot
6. silent running right as you get dragged out at interdiction (good timing needed/required) can let one get away in any ship
7. ECM module seems to give a massive advantage if timed correctly, as it does actually repulse the FSD shut-down missile but no effect against normal caustic missiles. Additionally Point Defense tries to shoot down both types of missiles, but seems to only be a help with the FSD shut-down missile (I've confirmed that personally...I think

).
All good tips to work with and likely more to come soon