Q1. in the case of gomarkets the cost is the difference between the buy and the sell price - what's called the spread.
so if you bought and sold a currency pair at the same time, the spread would be the cost of making that transaction.
say you can buy a currency pair at a ratio of 101...
just a note to go. there's a nasty EA called fx genius which tries to take advantage of slower broker feeds to 'cheat' out a couple of pips from brokers which dont update their prices quickly.
id hate to have restrictions placed on all of us cause of that nasty piece of work. so keep an eye...
do you have the original code (mq4) file? or only the ex4 file?
sometimes you need to re-compile the ex4 files after updates ive found in the past.
also, if they use .dll's their compiling can also cause the problem (assuming its not something totally unrelated as well).