Siegebreaker. 2H Hammer Marauder

Hi there. This is my first character and im not quite sure where to go with him and what possibilites the game offers to me.
I played to level 17 and now i think i have to settle for a more specific path for my character.

So, i want to make a class i would call "siegebreaker". Heavy full plate armor, one 2H hammer to smash down doors and walls, eating all the damage, attacking only slowly but nothing survives where he hits. I found the molten shell skill and love that! He can stand there and, hammer a campion down and then explode to erase all of the small creatures.

Now, my question, is that build viable?
http://www.pathofexile.com/passive-skill-tree/AAAAAQEAcrKlbuMraEWqDgowx0GqlrnlP71CjDFZfCxXerei0GrNsSBXEiGPI9E0PdfL1RfP0z_wezGTSfeiN6h2eE0ButSLxKsBzjiLANTk5hcVF9aodrQ9u6_foH3biS7mkKRw8W37pkM9xqwwCH1AqkgB8_9eeb9IzhPcDK8KxydoHOx64LEJTWag5Ugzp5wioB7CLZblK80SrI5yn1bUN8Qjf6gveomE1xwS3wMV1DsoLVU8SGJLgjy-rCpDudcLvPbO48G0Bz2hNr20s8HO0iiqDj5OBgP7Wu0OqmuudiASom6Q3gcsTK6fiHwlLQ2aWAlQN-joTWFxNlM_B54h3bR_EY6nLqI7xWUoW9k2OL6DfOE3lwhEtCgp-nfyvK3Wxo-cyXoP-lt5wZdTT2zC

I am not sure about the blood magic. I dont know if that fits well in the theme. Probably more suitable for a psycho marauder with a 1H axe and 1H mace who is a complete mental, hacking away everything.
For my feeling mana is quite rare and a bit more would be good. Or using blood magic.
Any experience someone can share about that?

EDIT: Changed it a bit, got the golem life regen.

Read my reply here.

The new passive Tree changes quite a lot.
I want to use chance to ignite as support gem for ground slam and the add fire aura.
My previous plan was to use blood magic, but to level the support gem i will need quite a bit on intelligence. Maybe i can skip bloog magic, take some -mana cost on skill nodes and be totally fine with a bit mana?
I could skip golem's blood and instead get the +% damage nodes at the start of the marauders passive tree (butchery) and maybe lava lash.

I dont know, i find it difficult to decide if blood magic is worth and how much mana i really need.

Just an idea: instead of life on hit with ground slam, how about mana leech?

Here my build, so far:
Marauder 2H maybe blood magic

EDIT:
Without Blood magic.
2H Mace Marauder without blood magic

I think i like him better.

I see ground slam with a mace as a stunner build mostly. Would you consider building around that? This means you get less returns with molten shell as you need to take physical hits for it to explode. I would suggest infernal blows in its place.

Suggestion
+7% hp regen
+91% max hp +30hp
+30% less damage from crit
+23% elem resist
+2% physical damage life leech
blood magic

+30% fire damage +30% fire damage with weapons
+90% physical melee damage with 2H mace
+65% stun duration
resolute technique

You can take hits not because of your armor but your hp and regen