I worked with both Kickstarter and Crowd Supply, and I have to say that the latter can help you significantly.

Cashflow is certainly an issue. In our 1st KS we definitely did significant discounts. Thankfully we remained profitable, but what we didn't really considered well enough was the amount of money you need to build inventory AFTER the campaign.

Rule of thumb now: 3x your production cost. 1x for manufacturing, 1x for various expenses including discounts, 1x for next batch.