A wrench that fits the hub nuts:   If your bike has quick release front and rear wheels, you don’t need this, but if you have an internal hub on the back, such as the NuVinci, a wrench that fits is a great idea.  99% of the time, this is a 15mm wrench, but you should check your bike.   A 6 inch adjustable wrench can also work, but it will be heavier, and when using an adjustable wrench, you do need to take more care to not round over the nuts.   A fixed wrench is the best choice.    Some multi-tools have a 15 mm wrench built in, but again, if you have limited hand strength, something with more leverage is a great idea.
This is the shop I hoped to find when I began commuting two years ago. I'm a daily commuter and I love knowing that these guys will help me almost anytime that I need it. Andy, Jake and Brad listen and make sure to help me as best they can and are always speedy about it. Additionally, they encourage me to do my own work on my bikes when I have the time/when they know I'm capable and I really appreciate that encouragement.
Some years ago, I used to live on my bike. Riding around daily through any weather condition was bound to quickly wear down on the bike over time. I like some of the stuff that you have in your toolkit. I would say zip ties are actually really convenient, because when something came loose you could go ahead and use those to fasten them down to keep on moving ahead until you had enough time to fix it or get it checked at a bike repair shop.
Modern bottom brackets use a sealed bearing type construction that keeps water and debris locked out, so they seldom go wrong. Maintenance is impossible so they need replacing when they do wear out. Older style cup bottom brackets need to be re-greased every now and again, and occasionally will need to have their bearings replaced. There are a lot more teeth on the chainring cogs than those on the rear cassette, so need changing less regularly. Cranks usually a solid one piece construction so there is not much to go wrong.