I'm not defending him or anything, but the reason he did all that was so she wouldn't be bored. Because in the beginning she said so herself, that she's someone who easily becomes bored. Which is why, when she said that maybe she should take other jobs, which are not your mundane office jobs ("adventurous" jobs), he(already fell for her and all) doesn't want to be seperated. So he proposed, but he felt guilty(because it was all based on his selfishness). And so to make up for it, he did all that to keep her on her toes and "waver", as in give her a sense of excitement. And about the 7 years thing. Maybe because of the "7 year itch". Not a 100% sure of this theory, but I think it's plausible.