They need to introduce shield blocks during casting.

I wouldn't change shield tron. It makes tower shields viable. Making it a 100% null physical damage will kill towers if my theory is correct and we keep rebuilding our damage reduction upon block back to 30%, making mid tier (kite) shields king again. Your suggestion would solidify that.

DV is suppose to be our (the tanks) HP. But I think they should just take out the "cure" part and just make it a raid wide AoE. As it stands now it forces you to anticipate the move that's about to come and put the ability up 30 seconds in advance for some healers to notice it and to cure you. Seems each time I throw it up, healers literately stop healing me, even with a macro saying it's up.

Clemency, I agree upon. The time it takes to cast it is rather long, making it a not so great option while Main tanking. The suggestion of shield blocks earlier would at least aid in further damage reduction during it's casting time, but a shorter cast(maybe 1 second less) would be nice.