If there were no spiritual consequences

To be able to fully envision a world of no consequence I would say you would have to be able to imagine yourself existing outside of time then imagine yourself being the "almighty", in every amazing and horrible situation you think is possible as victim, perpetrator and bystander, to be capable of anything without a hint of remorse or joy, it just is what you make it. Not just imagine it but immerse yourself in it, really feel and comprehend the total awe inspiring power and helplessness that you are. With great knowledge comes great responsibility and a wise person would use this kind of cold hard information creatively as opposed to literally. It's all about being able to entertain a thought. May also be useful in liberating yourself from such base desires for long enough to focus on achieving the glory of your seemingly impossible childhood dream/s, the ones crushed by cultural morality, conformity and social beliefs. So to answer question number 5 which to me sums up all of the questions, it is a liberating thought useful for helping to remove doubt from the mind.

1) Would your attitude towards life change?
My attitude towards my life would change.

2) Would your attitude towards other people change?
Unlikely. A lifetime of values and emotional attachments is not easily disposed of, even if logic permits it.

3) Would you take part in more selfish behaviours?
As long as they did not significantly affect those around me, yes.

4) Would you take part in fewer altruistic behaviours?
If I knew from the start, then perhaps. As it is now, I doubt it. Whether intuitively or through conditioning, conforming to my own moral code is less painful than acting against it.

5) Would you fell more liberated or shackled than you currently do?
I don't feel limited by my philosophy or theology currently so I would have to say I would feel more shackled by the limitation of my existence.

Were this the case, perhaps Yeats says it best,

"Endure what life God gives and ask no longer span;
Cease to remember the delights of youth, travel-wearied aged man;
Delight becomes death-longing if all longing else be vain.

Even from that delight memory treasures so,
Death, despair, division of families, all entanglements of mankind grow,
As that old wandering beggar and these God-hated children know.

In the long echoing street the laughing dancers throng,
The bride is carried to the bridegroom's chamber through torchlight and tumultuous song;
I celebrate the silent kiss that ends short life or long.

Never to have lived is best, ancient writers say;
Never to have drawn the breath of life, never to have looked into the eye of day;
The second best's a gay goodnight and quickly turn away."