In my opinion, proc styles are overpowered and should not be included. Large shield is not, and to be honest, I don't think it is a huge boost in pvp so I would not even discuss it. (maybe I am wrong though...)
Det 3 is the only reason for me to consider Thane. Is it enough ? Maybe yes, maybe not.
What about instead of doing changes over changes before it even starts, we try it out ? The server's team seems pretty reasonable and flexible to consider changes upon realization that something does not work. If it indeed does not work, a boost could & should be considered in spirit of diversity.
A lot of people will complain about "nerf" & "OPness". Well, if it triggers people rerolling, gearing up (including working brains over new type of templates) and playing different classes as the meta evolves, creating new encounter types and discussions on forums : why not ? To me this is what makes a server alive.
I'm fairly confident thanes Will be played because of det 3. They are a versatile class. It's not like a pure tank who's useless when rooted or snared. They might stay cc'd abit longer but other then that they will be great.