The commission is specified per side for a 1-lot EUR/USD trade and is charged when a position is opened. For full details on commission rates for other instruments, please refer to this link. No commission is applied to trades on Standard accounts for currency pairs and metals.
Detailed information on leverage ratios is available at this link.
The maximum total position volume is $1,000,000 for BTC and $300,000 for other cryptocurrencies. The spread for BTC starts from 0 pips.