A few points I'd reconsider:
track frame is not particularly comfortable for casual riding, and not very conductive to carrying cargo - two major factors that I'd say define 'city' bike. take a look at dutch city bikes for frame styles
internal gear hubs vs derailers. i find that IGH and other 1x1 cog setups to be higher maintenance than derailers.
for one they make fixing a flat tire more difficult, you need a big heavy 10" 15mm wrench in your toolbag now
also in terms of long term maintenance, as a chain stretches you have to constantly pull the rear axel farther back to take up slack -which then means you have to adjust the rear brake to match, and over time the dropout gets all chewed up from all the axel nut tightenings and becomes trashed
whearas with a derailer, the chain slack is automatically taken up by the pulleys; you can ignore it until it is time for a new chain altogether (just a little oil, same for igh); you can have vertical dropouts and never worry about axel slipping, replacement parts are common and cheaper than igh
solid 'aerospokes' there's no way to ever true the wheel if it does get banged up; and seeing as how this is a city bike being used for utilitarian purposes, repairability is a must...
Look into a Surly Troll frame, great for utility/city/commuter