I cannot see how any of the above has any bearing on whether he murdered.
Many young adults take gap years and travel, some work abroad for quite a few years. He was able to do it because his parents could afford it just as more parents can afford it these days. Many in their late teens early twenties also work at different jobs before settling down its part of growing up in the western world for those lucky enough to have the opportunity.
Yes and the raison d'être behind these gap years surely is that you sow your wild oats whilst you're young, get whatever it is you needed out of your system and then settle down to hard work and domestic bliss. We will never know for sure how Jeremy's life might have evolved had he not taken his short cut to madness, but the sad fact was the relationship he most wanted to succeed, namely that with Suzette, failed, leading to an uncertainty and crisis of confidence, exacerbated by his parents' lack of empathy and criticism. The tragedy was that they were moving in his direction, albeit slowly, the rumours that they were thinking of selling up may well have been true, but by that stage Jeremy had been inculcated by his idee fixe, and whatever his parents' plans for him was set on his murderous course.
