From the starting position it is not possible to make two moves with pawns from columns b and g. For example, p b11-b10 and p b12-b11 for black.
I successfully made those two moves on Black's first turn. I also did the same with Pawns in the g file. So, I didn't find this to be true.
Since the first move is not displayed on the board, on the square where the piece that made the first move stood, you cannot place another piece on your second move.
This isn't true. Maybe you tried to enter both moves at once in an incorrect format. Moves on the same turn should be separated by semicolons, and if you enter just one move at a time, it will update the board and prompt you for the second move.
I successfully made those two moves on Black's first turn. I also did the same with Pawns in the g file. So, I didn't find this to be true.
This isn't true. Maybe you tried to enter both moves at once in an incorrect format. Moves on the same turn should be separated by semicolons, and if you enter just one move at a time, it will update the board and prompt you for the second move.