IC Markets is good and they do not hold accounts ever for withdrawal. But you do have to realize that IC Market is NOT a true ECN either. They are not too bad of a broker but they do NOT operate on as true of an ECN broker as brokers LMAX, IB or Baxter or the other prime brokers. You just need to keep this in mind when you trade with them otherwise they are not too bad. They like to make themselves out to be but in reality they are not like the majority of the foreign brokers in the world. They are what is called an "AB Booking shop". They categorize clients into 2 types or 2 "books". For those who trade with large account balance, at least $10K+ and trade really well, they categorize these clients as "A Book" or A type clients. For these clients, they send their orders to real 3rd-party like their "liquidity providers" to be executed. The rest, those who trade with less money in their account with large losses, for these clients, AB Booking shops take the opposite side of the clients' orders and execute their own clients' orders themselves. That way, those brokers wins either way. They win by trading against the losing traders aka their B-book clients and earn commissions from the winning traders, their A-book clients while their "liquidity providers" take on the risk of trading against those winning traders. If you ask them, they will never admit to it. They will just tell you "it's proprietary". But if you check their "Disclosure Document" which is what all Australian brokers licensed by ASIC are required to publish on their website, it is stated clearly there that they do become principal to your trades, aka taking the opposite of your transaction basically trading against you.
Those are what is called "bucket shops" where they exist solely just to make money off you by trading against you. And if you somehow made money, that's when they don't let you withdraw your money and/or even ban you from trading with them. That's the nature of trading. If you are making money then whoever takes the opposite side of your transaction must be losing. You think those brokers would be content to let you win all the time at their expense when they are not even charging you commissions? They will be like just giving you free money and why would they do that?