This site is a complete scam. I deposited 0.75 BTC to play roulette, non of their games would load (see screenshots below). I figured oh well, I'll just cashout and play somewhere else.
If the games don't load it is a problem on your end. Which browsers are you using, are they up to date? Have you enabled flash for the site? Is your internet connection fast enough?
Of course you need to turn over the deposited funds before making a withdrawal. That is nothing new in the casino industry.
What are the requirements for making a withdrawal?
Firstly, verifying your account via email.
If your last deposit amount is equal to or greater than 0.3 BTC (or equivalent in other currencies) you have to turn over your deposit amount at least once, and the amount of the withdrawal should be at least 0.004 BTC (or its equivalent in other currencies).
From FJ FAQ page >
https://fortunejack.freshdesk.com/support/solutions/articles/31000146400-what-are-the-requirements-for-making-a-withdrawal-