I am assuming that brothel encounters are not neccesarily the highest on the list of things absolutely required due to the other encounters that are seemingly inescapable in the later game, resulting in those scenarios getting animated first.
Also when playing, in the beginning I used to have the same problem with food, but I later got better managing it. Hunger charm is something to look out for, which is found in the first map. Also try not to focus on getting too many companions initially. Kylira is the one that has the best perk of healing you during battle. Also spending money on food is pretty much the only thing I do in each town. Another way I don't let myself get too low is by going to the second and third worlds as soon as i can. Drinking from healing ponds also work out well. There are many more opportunities to get food. also if you are desperate for food, you can always suck a bit of dick now and then.(I am omitting some information because I dont want to spoil the game for you, but if you would like to know more about food in game, just ask). If you are losing health and you want to regain it, talking to kylira heals you to full i think every time,so you can save on food if you are low. also casting sleep, then heal, then attacking can heal you right before a battle ends.
negative modifiers like that aren't too bad in later game, except dignity and purity. It only really affects merchant who offers wares that aren't really essential to the game anyways, but mostly for fun kinky options.
also there are ways of recovering willpower, which are demon lifesuck from horrible presence encounter, and getting screwed(willingly) by a wereslut.
The willpower is there to prevent certain game overs, but being too receptive is ignoring a great deal of the fighting game mechanics which are supposed to mesh together as well. a good balance is nice.
charms that are 200 gold piece arent too bad. you arent meant to use too many of them and spam them. I usually use money i get from defeatingg the goddess of the mountain to get one or two. also you dont need to obtain really any charms to beat the demon king either. also if you have high enough agility, you can just steal them. also certain gear has a good deal of bonuses such as gauntlets of strngth, helm of perception, the agility high heels, and the cage of power.
I kinda wish that spells could stack burning, ways to use paralyze as mage in an easier manner since it just got nerfed,(mage playthrough is a tad difficult but if the mage class had a quickcast perk then it would be pretty cool, or it starts out with more soul crystals or spells could deal mor damage idk).
there is some pretty good content with urka and the warlock which i think is written pretty well.
I mean you can still have sex with monsters without negative modifiers. I often use handjobs to take care of them and still retain purity.
If you have any questions I am more than happy to answer.