Heya all!
I've been thinking a bit over the monthly income rules. Have you ever noticed that most of the careers that earn a lot of monthly income also has at least one free trade skill upon character creation? All of these classes earn among the most. Now, income is supposed to represent the character using his free time doing what he's good at. They are graded after social classes, and a guardsman knows best how to fight, so he would do mercenary or bodyguard duty. Not a lot of pay, but life is life, eh? Clerics are showered in gelt by the people, through donations, but I bet also by puting those free two tradeskills to good use.
The trade skills are not very attractive ones to take, aside from perhaps copyist which you can use in forgery. So I was thinking, that by taking a tradeskill, would bump you up to the next income level. So if a psyker for example, whom is Supline class in terms of income, took a +10 advance on his chosen trade(or a new one all together), he would bump up to the next income level, learned class. I think this is a neat way to keep the trade skills a little more fresh and attractive, and giving players options to earn more monthly income.