All types of corps.
Go!

You should sit in npc corp because no one wants a thief with 5m sp.

25mil sp, and not a thief.

joining corp is to do something else as sitting in high-sec and killing NPCs

but it depends on what u wanna do:
some are Pirates: searching low sec and killing inisent noobs
some living in a wormhole
some in 0.0 systems
and some in high-sec but allways at war

the other types are not so interested

lol.. not iso this.

iso of "Tell Me Why I Should Join Your Corp"

corp?

The Zeitgeist Movement - will help you out with a ship if it get's destroyed. Friendly people - growing.

wheres the isk coming from that helps with ship losses?

sure from 15%+ taxes