Since then, I’ve found a few decent alternatives to my dilemma: The Venzo Pro Mechanic Stand that runs at about $88, and the Cave Competitor Service Post for $59. While there are other alternatives out there—sometimes cheaper ones—these are the two that I think are actually worth the price. I can’t really vouch for any others out there. But there just ain’t getting around this one. You’ll need something to hold your bike while you work on it.
Spare tube:  Sometimes, a tube is just too damaged to be patched, or has had a failure such as the valve stem breaking off which isn’t something that can be patched.   To save weight and space, I usually keep a lightweight version of the right size tube for my bike.   Since one of the first things I do with most bikes that I own is switch them over to heavy-duty thorn resistant tubes, I just take one of the originals and put that in the toolkit.
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.