Like you, I used to have shoes for cycling and shoes for work.
I resolved the issue by replacing my clipless pedals and putting nice large platform pedals (no traps) and using my work shoes. Much simpler. If it rains, get some of those motorcycle overbooties, they work very well and can be stowed away. This assumes you arent using that ride time as training time, more as simply commuting with some lite exercise benefit.
As for a thinner gi, consider getting regular cotton pants from whomever, but for the jacket this seems promising...
Note I was going to suggest the Bujin 8oz. jacket, but that no longer appears on their site, and frankly for the price, I was never that impressed with the wicking material.