Can you elaborate "no deposit abuse"? I mean, if they are giving away free coins, why would you have to make a deposit? How does depositing helps you to prevent people from abusing this promotion? Users can simply still abuse it by making multiple accounts. Playing for a while. Making a small deposit and withdrawing it. You see, depositing isn't stopping them from anything.
To test out the site before you commit. Like those free samples you try from shopping malls, the same concept applies. If you like it, you stay. Else, move on.
For instance, you create multiple accounts using the same referral code. So let's say it's 10 accounts and each refcode gives out 50 cents, then that makes the total $5.
So you just decide to go all-in in roulette. Out of the 10 accounts, you won the bet on 5 accounts. So you still remain with $5 (five successful 50 cents bets). Then you withdraw. If there's no deposit measures in place, the casino would lose $5 because someone managed to create duplicates just to withdraw the "free" money.
This is just one scenario how these kind of things could be abused by one, let alone by many.
But then with the wager thingy, you must fulfil a quota bet first. So it's not solely depositing and then withdrawing the extra, the requirements are still prevalent.
Users can simply still abuse it by making multiple accounts. Playing for a while. Making a small deposit and withdrawing it. You see, depositing isn't stopping them from anything.
Of course, then there's the house edge. Some will be lucky enough to withdraw, then continue playing since they feel confident while others rip. Then the former will eventually lose to the house edge. Tadaa.
Casinos will take (small) short-term losses for long-term gains.
I doubt it. They'll giving you away free coins to play into their casino and right after you won huge amount and trying to withdraw your winnings, they suddenly would asked you to make a deposit first for the withdrawal to be process. How's that sound?
Withdrawal worth more than 30x to what they asking you to make a minimum deposit first.
Of course there are shady ones which won't inform you beforehand. But before you start making those bets, try to make a withdrawal and the terms will usually appear. Alternatively, check the TOS/ FAQ. Here's one from the casino I play on; it clearly states a new user has to make a 1,000 coins (~$0.60) deposit and bet twice that amount.
Some instate levels restrictions, others like Stake incur a 5K Sat fee to withdraw with no minimum. Since I've played on multiple casinos, I can attest there are legit ones, and not every "deposit first to withdraw" are out to scam your money.
In the end, always check the reviews before you start playing with a free coins code. Worst case scenario, you'd just waste your time.
And yes, the 30x is indeed true to some. I wouldn't recommend playing on those but that's the restriction if you don't make a single deposit (would be more lax once you do). If you're cautious, play safe; few cents bets on BlackJack, on Plinko, etc...