I have that same Topeak bag and rack. Make sure to measure your wheel, the first rack I ordered was too short and didn't have enough clearance so I had to go with the 29er to fit my bike. Love the bag and system in general but I do at time supplement with my GoRuck GR1 backpack. Mainly because on some days I have to carry a bit more so I split the load.
Friday's are the one day that I don't ride because plans for after work are always changing. Any other day of the week works pretty well for me but I do stay away from Fridays. As others said, check Google Maps and put in your trip, there is a bike icon that you can select and it will pick up any MUP's and show alternate routs.
The other thing I did was go out and drove a few different routes to see what trails and paths I had available to me. Just discovered that one road added some MUP to a section that didn't have even a sidewalk so that just gave me yet another route I can take. I don't do roads, I'm just a casual rider so unless I'm in a neighborhood I try to stay off the roads.
The more I ride the more I enjoy it and what I like is I get to see and hear things I wouldn't have noticed before in my car.