EXP and Enemy Lure

Hello! Right now I have a level 11 character, and I'm debating whether to get Enemy lure or not.
From what I understand, the intent of Enemy lure is to function as an EXP booster, placing the player some levels ahead of the enemies you face. If the player takes enemy lure at the top of say, anomaly, and fights every encounter and explores every sanctum, how many levels ahead of the EXP curve would the average player be at Tower 30?
I've also noticed that while fighting summoned minion enemies (like the hounds with Actaeon or the villagers with Asrai) that one does not get experience until the demon joins you. Do minion-class enemies give no EXP, or do summoned units specifically not give EXP?
Does recruiting demons (and then immediately deleting them) have an EXP malus compared to punching them in the face, or are they the same?
How is EXP gain in general calculated? Is everything just worth a flat chunk of EXP, modified by difference in level and with every level requiring a flat but increasingly hard to get amount of EXP, or is it a dynamic calculation including heroism/unique/minion status, level, and modifiers where two foes are worth the same EXP at level 5 or 30, but it takes increasingly large amounts of EXP to level?
From what I understand, the intent of Enemy lure is to function as an EXP booster, placing the player some levels ahead of the enemies you face. If the player takes enemy lure at the top of say, anomaly, and fights every encounter and explores every sanctum, how many levels ahead of the EXP curve would the average player be at Tower 30?
I've also noticed that while fighting summoned minion enemies (like the hounds with Actaeon or the villagers with Asrai) that one does not get experience until the demon joins you. Do minion-class enemies give no EXP, or do summoned units specifically not give EXP?
Does recruiting demons (and then immediately deleting them) have an EXP malus compared to punching them in the face, or are they the same?
How is EXP gain in general calculated? Is everything just worth a flat chunk of EXP, modified by difference in level and with every level requiring a flat but increasingly hard to get amount of EXP, or is it a dynamic calculation including heroism/unique/minion status, level, and modifiers where two foes are worth the same EXP at level 5 or 30, but it takes increasingly large amounts of EXP to level?