Lifeline Deck

Lifeline is a really awesome card, even with it's stupid errata that makes it kinda symetrical. I have designed this deck for a true "casual" experience. I don't expect any real permission decks or any other not very fun decks. Without any more blabbering here is the list, things I like and problems I have encounterred.

the Circle of Life

Creatures
4 Birds of Paradise
4 Soul Warden
4 Mogg Fanatic
3 Voidmage Prodigy
3 Ravenous Baloth
4 Raven Familiar
3 Phyrexian Plaguelord
2 Viridian Zealot

Accelerators
4 Dark Ritual
4 Show and Tell

Lifelines
4 Lifeline

Lands
4 City of Brass
4 Thran Quarry
3 Grand Coliseum
3 High Market
4 Island
3 Swamp

I like this deck a lot for 4 main reasons
1) The draw engine, raven familiar and high market/plaguelord, is so much fun. Once it gets going it can be insane.
2) This deck plays alittle bit like reaplace did in that it combos out, but not without player interaction. A good call for casual.
3) It has lots of answers that are permanent and double as threats, therefore it can be reactive and agressive at the same time.
4) It is five colors of fun that performs well in multiplayer and one on one.

I dislike the deck for four other reasons that I hope you all can help fix
1) the mana base is really shaky. It needs all five colors over the course of a game.
2) I don't always get the creatures I want. I am considering adding Survival or living wish and a toolbox sideboard to fix this, any suggestions?
3) The Plaguelords are inefficient in killing other creatures but allow me to use rituals that would otherwise be dead/ get my draw engine moving. I like Duplicants in their spots, but then I need another lifeline enabler. any suggestions?
4) The voidmages are a little slow for my taste. Are there any better, cheaper counter creatures?

thanks for your help.