I can't answer to your questions because I lack the knowledge to give an informed answer. They would be mere conjectures and speculations.
However, concerning your interests, I can tell you that procuring "far more loot than normally" is the easiest way to be banned from the game. There is an automatic ban mechanism that takes into account the frequency of looting and the amount of looted spots per area that will prevent your character from looting and gain experience for 24 hours once you triggered it. It's not an heavy punishment, yet it will defeat the purpose of having used those kind of hacks.
The most common "lethal combination" of hacks is the one that enables all loot spots joined with the fast-loot hack. Unless you are able to pace yourself and limit you pillaging rampage, you will trigger the ban automatism in a few minutes. I am unaware if, after a few times you incur in the 24h ban, you might be banned manually by the moderators for repeated hacking. My main character has been banned 3 times so far, with no permanent consequences.
Exp hacks are not detectable unless checked manually. Unless you gain much more experience that how you are supposed to with your level and equipment, you shouldn't raise any red flag. Keep in mind that if you happen to be the Top Survivor of the week, your account WILL BE checked manually and you might be permanently banned. I suggest to use Exp hacks with moderation, being careful of not attracting too much attention (like being in the Top 15 survivors, statistically the most watched positions by the other players). If someone gets suspicious he will report you.
The most lethal combination, in this case, is the x900 damage multiplier hack along with the XP bonus, because together they would allow you to destroy hordes of enemies and bosses in just a few seconds, dramatically increasing the XP gain. I am not aware of any player banned for using those cheats, though.
A generic advice regarding the use of hacks is to never use them in PvP and Multiplayer. Many people hate cheaters and will not hesitate to report you. Do not overdo and be wise.