There are different margin requirements for differen instruments Forex is usualy 0.1% / 0.2%
CFD;s are Different higher Margin from SpreadBeting account. also the leverage is higher too yes
A True ECN/STP may not fill your exact price because it depends on the liquidity providers prices at that time on the Network .
a not so good STP broker may only have 1 liquidity provider and it might be a small bank or another sister company.so your order will be filled because they control their prices.
A TRUE ECN/STP will charge or credit swaps and charge a small commission.
It's finding a decent broker thats the tricky bit.
ECN = Network of different liquid providers
STP = Maybe small pool of liquidity thet they control if its a (dodgy broker)
The main difference is is the commission. On ECN accounts traders are charged a fixed commission for opening and closing trades and spreads depend on the prices of liquidity providers. On STP accounts no commission is charged but the mark-up is added to the spread of liquidity providers.
LQDFX looks like Market Maker not very good reviews
Where are you based.??