I gave your armory a very quick view while im sitting on a boss, but itemization looks fine. It is somewhat accepted that threat stats are not necissary for tanking at the moment. Tanks only have threat issues if:
(If threat is a problem for extended periods) - Bad rotation or you are severely outgeared by dps.
(if threat is a problem on the pull) - Bad pick up, insufficient MDs/threat cooldowns/patience from dps.
At last, i dont think ZA-ZG will contribute significantly with better gear. In your position id farm world tree marks, reputation with avengers, and tier 11 raids.