Technically, a character could have : a status bonus, a circumstance bonus, an item bonus, an untyped bonus, a status penalty, a circumstance penalty, an item penalty and a MAP penalty.
The enemy the character is trying to hit could also have a status bonus, a circumstance bonus, an item bonus, a status penalty, a circumstance penalty and item penalty.
Frankly, I think it is more productive to speak in terms of actual play. From my experience (<4 level and characters that didn’t use a lot of buffs or debuffs), every turn there were 2 or 3 effects in play + MAP.