For on-base percentage, it still counts as an at bat and the hitter is not credited with an 'on base' so whether its an error or a fielder's choice the player's on-base percentage will decrease
No. On-base percentage is calculated by adding hits, walks and hit-by-pitches and dividing that number by the sum of all at-bats, walks, hit-by-pitches and sacrifice flies. (Source:...