If I use BuyDelay=1000 (ms) in the strategy settings on the Buy conditions tab, at what point does the strategy check the balance, at the moment of detection or after the delay expires?
Strategies with a non-zero BuyDelay parameter check the balance after the BuyDelay time expires, i.e. just before placing a Buy order. In your case, the check will be done after the 1000 ms delay expires and if the balance is sufficient, the strategy will immediately place a Buy order.