As a tank your role is to hold aggro and reduce the damage you take. The following LI i would recommend you slot but remember there is no best Li setup.
For your spear add Spear Gambut Parry Rating and for javelin add Fist Gambit Evade Rating. If you are currently doing fine i would say dont change anything because its a lot of resources in changing LI because you will need to tier them up. If you did add those two LI you wont notice any major difference in your play if am honest.