You can raise stats by visiting the Mutatio store in the Mall, you sell off a temporary point (best done when it is maxed out and as a male), and then turning into a female to buff the stat (the only thing this doesn't work on is cock size, for somewhat obvious reasons), you can then regain the lost temporary point and repeat until you are happy with your stats. Everytime you use Mutatio the amount of essence you gain from selling stats drops a little until it hits a hard cap of 50%.
If you play as the loser Achetype, and reduce your base scores all the way down to 1 (3 max), you can raise temporary stats as high as 5, which are then reasonably cheap to buy up, and you get massive bonuses to XP gains. Playing mostly as female really helps this play style, as females have lots of ways to boost charisma (Make up, hair do, fancy clothes, and a relatively cheap watch), and in addtion to having a big boost to learned XP from having shit stats, as a female you can boost gym gains even further by having 7 sets of gym clothes which all give a boost to XP (preferably the double xp ones) and engage in the Sexerise events, these provide a HUGE boost of XP if you can pull off the conditions. The Redhead player character is best, as all you have to do is wear the bikini which Callie leave behind in the intro, while visiting the beach and explore the jungle, once you have met up with her and agreed to help her out, buy the blue exercise clothes and when visiting on a Thursday, you will automatically wear it and have the option to trigger the event. The only real downside to playing the loser is that you will need to get a couple of drinks inside you before you can work up the courage to speak to any girls in the pub. At the beginning when asked if you would mind taking x-change, I would avoid saying you are okay with it, as this shrinks your cock, which can lead some of the pub girls to mocking you mercilessly when you take them home, but hey, if you are a sucker for punishment, go for it.