They are all possible in the current version. For most of these you just need to grind them out. Like Brothel Baron just requires you to make a certain amount of G in the brothel, Transformer just requires an amount of transformation fetish points which you earn by using Vicis. The other two require you to meet specific conditions, but I think they’re self explanatory. For Lemming, that’s the only one that’s actually missable as there’s a finite amount of reputation points in the game, and if you miss enough, it’s possible you won’t be able to sleep with him until a future version when more points are available to earn.