What skills do I need that are the hardest to level? I was thinking I could cheap out on combat stats and grab diligent and train them myself, hunting also could be supplemented with wildborn. Intelligence seems hard to level but I also dont know what it does.
Technically, you don't
need any skills, as you can rely on other npcs skills for everything (including sex, if you make sure that they are very happy and have undying love for you).
With that said, there are obviously skills that are more or less useful. Intelligence is one of the more useful ones and also very difficult to increase, so I currently build characters with that one maxed out.
Survival is useless as team members survival skill also counts during hunting.
Combat skills can very easily be trained in the backyard.
Science is useful for hacking vault doors... But you can compensate with geek team members for that.
Academic sometimes helps a little during quests but is mainly only usefull if you want to work as a professor or train your slaves to work in the academy.
Stealth is useful during quests and a real pain to train to high levels via hunting... But, you can typically just fight instead of relying on it.
Charm, is very useful, but also very easy to train during seductions and you can even pay to increase it via plastic surgery, which is suprisingly cheap at $7k for 5 points, up to 89.
Manipulate is very useful, and quite time consuming to increase, but you can use charm instead, so you don't really need it.
Bondage is very useful, but relatively easy to increase in the dungeon and during seductions, so it is not needed during creation.
Flagelation is only used as foreplay in the dungeon, and I prefer to keep it low, since failed flagelation attempts have a chance to decrease corruption, which is otherwise very hard to do (on the rare occasions that I want to do so).
Copulation is very useful as it has lots of positive sex related effects, including a small chance to increase girls nymphomaniac trait if your skill is 66 or higher... But, since it can be increased simply by fucking, it makes little sense to drop points at it. It will increase eventually, if you just keep fucking... And if you can't be bothered to do that, then it is not useful anyway