You will die. Not nearly enough defenses and you skipped over some potentially valuable nodes on the way to Vaal Pact. Probably won't even be able to keep yourself alive either via leeching. You don't hit hard enough or fast enough given the thin defenses in all likelihood.
No. CoDT now has a level limit.If you put a gem with level 10, for example, together with a level 1 cast on damage taken gem, the former gem will have a level of 1 instead of 10. I think it's that, it reduces the other gems' level to the one cast on damage taken has.
The level requirement of gems augmented by Cast on Damage Taken may not exceed the level requirement of the Cast on Damage Taken gem.
http://pathofexile.gamepedia.com/Cast_when_Damage_Taken