Here my question, do anyone know another great crypto exchange like MXC, where I get higher margin amounts? Would like to buy OCEAN on margin (but not 3.5k capped margin on Binance)
Well that's you can get from Margin binance trading. That's a lot already, if you have spare cash then do the future instead the margin features. Borrowing and repaying could be sour if you ruin your trades especially if the market is so volatile.
Generally, trades with leverages x50 or x100 is almost suicide, IMO. Such the trade and leverages are created to enrich exchanges and whales. Retailed traders are liquidated by such trades.
If you don't know the market movements. We have technical charts that guide us. Suicide it is for those who just open up an order not having confidence of the possible move. But for those who knows 80% what will happened based on chart could be called legend for opening a leverage with huge such as 100x.