I don't mean to criticise (by which, I mean I do, but I don't mean to offend), but although you say you don't want to use the Spirit Shaman class, you seem to be using a few of its attributes to replace those of a Druid.

1) Chastise Spirits

2) Animal Companion exchanged for Spirit Guide

3) Dropping spont. cast Summon Natures Ally

In fact, of the 3 primary Druid Abilities (Wild Shape, Animal Companion and Spellcasting), you appear to only actually have one of those (Spellcasting) and even that you've put a self imposed limit on. You have taken Aspects of Nature instead of Wild Shape, which I guess you couldn't by using the Spirit Shaman class, but apart from that, why do you particularly want to use the Druid as a base class? To my mind, you're making excess 'work' for yourself to tailor the Druid to what you want when the Spirit Shaman is as near as damn-it anyway. SS and Druid share the same BAB, HD, Skills/lvl, Spell-list and one casting stat. With your modifications, they now share Chastise Spirits and Spirit Guide to. The only difference I can see is that your Druid has Aspects of Nature whilst the SS has stuff like Ghost Warrior and such.

So, before I give you any advice (which I can and will), answer me true: Why Druid and not Spirit Shaman?