Tank mara( Tempest Shield, Molten Shell, Searing Bond, Viper Strike)

Hi, I'm trying to do Mara build that basicly kill mobs by tanking dmg. I use also Searing Bond and Viper Strike because they do a lot of dmg without any dmg node so far. But i would like somebody to review my build and give some feedback. This build relys quite much on some of the uniques.
Link to my build:
http://www.pathofexile.com/passive-skill-tree/AAAAAgEBBS0OPBRxFm8aMho-GlUbyB0UJy8oxSj6KS4ppTH7NZI26DbpOlI9_ECgQYdDMUrITDVOKlFgVElVtVXGWGNYr14TXz9gS2EhZKNnvW6qcH107XgNeu98uH_jgseE74jxjM-PRpuhnrmezZ_LoLSnCKcwqW6playvtfK2Qbc-uJPBBMOGxtjPZdDQ0Tba3eNq45_nkevu7m_vDvGs8i_zBvO-9kj56PrS_go=

Gear:


I also have this waiting for level 70:


I'm opened for any advice to improve my build. I have some questions too:
1. What support gems should i link with Tempest Shield(maye life leech for more survival)
2. Should I go for more block chance(atm I have with my TS about 75%)

Ty for feedback and sorry about my bad english :D

Based on your goals, it seems like the following would help:

- Aegis shield would fit your preferred play style perfectly. I'd focus on that.

- A 5L or 6L BP is also a must IMHO.

- Rainbowstride Conjurer boots would be nice for the spell block and resists.

- I'm one of the few molten shell fans. I like to pair it with faster casting so you can spam it and have it up constantly for increase protection and damage