I had tried with EURGBP, without leverage, and there was the problem of limit orders with forex, the price went way above my order and I basically entered the trade with a loss. It was a small position though. Haven't you said that with CFD you always lose the spread?
Limit only affects the fill price, not the prices immediately afterwards. demo more. talking of which, try a CFD demo at IBKR. you'd need yet another sub-account. I couldn't say; no you can't trade inside the spread in any of the brokers ordinarily but IB is possibly different as they'd have just wrapped the existing ECN with a CFD wrapper. Tight spreads though, you'll have difficulty splitting them mostly.
Limit orders in forex often execute at the specified price but still incur the spread. True ECN exists, but many brokers operate hybrid models. Retail traders face broker markups and conflicts of interest, making futures a more transparent but capital-intensive alternative.
Let's say I put a buy limit at 100, the price goes at 100 and it doesn't open. Then it goes at 99, still not opened. Then it goes at 98, opened. So I bought for 100 something that was worth, when I bought it, 98. So I paid the spread. That happened even with IdealPro.