[1.0.0] Life based bow build help (IG,US,IR)

Stats:
+210 to Dexterity
+200 to Strength
+20 to Intelligence

Keystones:
Iron Grip: The increase to Physical Damage from Strength applies to Projectile Attacks as well as Melee Attacks
Unwavering Stance: Cannot Evade enemy Attacks
Unwavering Stance: Cannot be Stunned
Iron Reflexes: Converts all Evasion Rating to Armour. Dexterity provides no bonus to Evasion Rating

Life:
+42 to maximum Life
96% increased maximum Life

Mana:
80% increased Mana Regeneration Rate
32% increased maximum Mana

Physical Damage:
122% increased Physical Damage with Bows
8% increased Melee Physical Damage
12% increased Physical Damage

Cold Damage:
30% increased Cold Damage with Weapons

Resistance:
+10% to all Elemental Resistances

Cast Speed:
6% increased Cast Speed

Armour:
52% increased Armour
64% increased Evasion Rating and Armour
Ignore all Movement Penalties from Armour

Evasion:
4% increased Evasion Rating per Frenzy Charge

Attack Speed:
10% increased Attack Speed with Bows
58% increased Attack Speed

Critical Strike:
30% increased Critical Strike Multiplier
200% increased Critical Strike Chance with Bows
70% increased Critical Strike Multiplier with Bows
50% increased Critical Strike Chance

Charge:
+2 Maximum Frenzy Charge

Movement:
10% increased Movement Speed

Accuracy:
10% increased Accuracy Rating with Bows
20% increased Accuracy Rating

Misc:
+2 to Melee Weapon and Unarmed range
61% increased Projectile Damage
20% increased Projectile Speed
35% chance of Arrows Piercing

Link:
http://www.pathofexile.com/passive-skill-tree/AAAAAgAB1QAb-rXyMgl4DcAPgwnV-NwVpBlaGjH6hxlrJDsoTiqxMEMxfyvDOm49tkFgQ2xGUUfKStJNOlLnVPlWplc6WFpSm11lTepi-WMIZ25pcmypbt9vMHwyfiF2voo1kmqTA5byl82YR36omqCf_o_EoqGkKaVvnr6nbqpYr8qpBbUxnpu1jb_EuN7GSsify4bOPs_-yKfU6NaE2QR-4ds51CXfX-FN4wHcd9S95gHnNuiV6SLq1e0V8G_yzeok_Xb3

i made up a scion bow build that hopes to be relatively balanced between survivability and damage. Some questions: is investing in mana regen a waste of time when I can use something like mama leech (from gear, not gem)?
Are the evasion nodes worth it near the middle of the tree? It's about 140% evasion rating for relatively little points (~8 points).
Am I missing out on anything important like going through the shadow area for increased crit/lightning damage? This sort of ties in with my last question: what skills should I be using in a build like this? Lightning arrow linked with LMP and damage supports? Ice shot any good? Is split arrow or RoA aoe better?

Thanks for the feedback.

Questions:

1) Yes. If you got enough mana leech you don't need any regen at all.
2) Depends, usually yes. If you don't have any armor you should get Iron Reflexes to convert it all into armor. But I see you have done that already.
3) Your dmg is phys crit based. I recommend to use Lightning arrow to shock enemies. You can also check my LA guide if you want to, there is a useful combination of lightning arrow and other gems you could use.

This is a LA version of your build:
http://www.pathofexile.com/passive-skill-tree/AAAAAgAB1QAb-rXyMgl4DcAPgwncFaQZWhox-ocZayQ7KE4qsTB_K8M6bj22QWBDbEZRR8pK0k06UudU-VamVzpYWlKbXWVN6mL5Y25pcmypbjB8Mn4hdr6KNZJqkwOW8pfNmEd-qJqgn_6PxKKhpCmlb56-p26qWK_KqQW1m7WNv97GSsify4bOPs_-yKfU6NaE2QR-4ds51CXfX-FN4wHcd9S95gHnNuiV6SLq1e0V8G_yzeok_Xb3q8WsWYjx52P-CvJFOuEzDP4rGdX_3gzypcvEuNX4MZ42PYhrGdequKp_jX0=