First, I said 'I would give', because I'm not gamemastering, and not thus taking decisions.
You're right, there is no cost at creation for a double initiation. The cost is within the game, with double tithing, and double the time due to cults, double sacrifices,... Enforcing this is part of GM's task, as it is more linked to the setting than to the system.
I would not give anything extra for single initiation character, as it is, for me, a choice made by the player (with GM approval, of course) to have a single or a multiple initiation. If given the choice, I would probably choose a single initiation, but this would be my choice, and I wouldn't feel cheated vs people who made a different choice.
For the dual occupation, this is an other point I hadn't talked about. We liked, in RQIII, having characters that spent their previous experience with several careers, creating mixed personal histories, but I don't think it is possible with RQG.
Kloster