Intereting builds, I'm glad to see they work so well for you. I'm still not sold on Twice-Born Star but I can see its appeal. If I was going to go tank I think I'd do something a bit more unorthodox and use 3 pieces of Armor Master armor + 2 pieces of Armor Master 1H/S just to proc the 5-piece bonus and then use 4 pieces of Kagrenac's armor + Kag's Resto for the 5-piece. Use Willpower jewelry to complete the build. This would let you stack resistance with Rune Focus and proc Armor Master with either Annulment or Evasion. Then you could back bar for a quick revive or shift to offense with the added spell damage. I haven't run the full stat comparison but you would lose a mundus and stamina but gain resistance, spell damage, and revive speed. Personally I'd run this with 5 light, 1 medium, 1 heavy but I guess you could do 5 heavy, 2 light.

As for your offensive build, TBS seems more viable here but Julianos may change this. I'm still a fan of Kag's though so it's a really tough choice. The only thing I would probably change for sure is to drop the 2H + Resto and go DW + 1H/S since Orsinium will make DW = 2H for spell damage. Resto is good if your regen is low but I find 1H/S makes me more survivable, which is what I want on my back bar. You also get an extra set item so you could sqeeze in a 4-piece Magnus/Mara for a well-rounded build or go 3 Torug's + 1 Kena or 4 Overwhelming Surge for a bit more spell damage. I'm still not sure which 5-piece set I would want though so this build is really flexible. I'm leaning towards 5 Kag's + 4 Magnus + 3 Willpower though as this lets me adapt with jewelry enchants a bit more (just as you mentioned) and my regen should be good enough to not use a Resto.

Again, your builds look good but as you noted the Templar can be designed to do almost anything so it really depends on your playing style. Let us know how you update things after Orsinium though.