crit spectre throw marauder

hi guys,

I am new and would like to seek some help in answering my qns on my first character. :)

thank you for any input.

I would like to try to go for all the crit chance/multi nodes when starting as marauder.

http://poebuilder.com/#builds/ekenikichi-ekenikichi

I would like to ask:

is the Iron grip node important to have?
do spectre throw have crit chance/multi on them or I should do infernal blow/domintating blow?


are there any skill nodes that I should have?

regards,

eken