My suggestion to you is to do a complete Load Calculation for this location, based on what will be used under the new Tenant.
You could do a simple load calc to verify the existing load / demands, which would be helpful to submit to the Utility Company and the Building Department to describe the need [possible] for an increased service size.
The Utility people should have a copy of the original load calcs for the existing service, so maybe they can submit a copy to you.
Anyhow, just quickly looking at your description, it sure looks like an increased service size may be needed [???].
Your load calcs will determine if this will be needed or not.
When doing the load calcs, use the Volt-Ampere rating of "Non-Linear" equipment, rather than the rated wattage.
Looks like the only True Power loads you have listed are 2 toasters, the water heater, and possibly the HVAC heat strips [if the HVAC is a heat pump, then they are most likely going to use Apparent Power].
All other loads are Apparent Power loads.
The True Power loads can be figured as Watts [or KiloWatts - "KW"]. These loads will draw a fixed amount of Amperage at a fixed Voltage, at 100% Power Factor [or very, very close to 100% PF].
In other words, if you have a True Power load of 120 Watts at 120 Volts, the Amperage will be 1 amp.
The Apparent Power loads should be figured as Volt-Amps [or KiloVolt-Amps - "KVA"]. These loads will draw more current at a fixed voltage than what is shown in wattage on the nameplate [or other documentation]. The level of current will depend on the Power Factor.
In other words, the equipment may list a True Power consumption of 100 watts @ 120 VAC [which would equal out to 0.84 amps @ 120 VAC], but in reality it could draw 1.0 to 1.5 amps @ 120 VAC. If the current drawn was 1.5 amps, the Apparent Power would be 180 Volt-Amps [VA].
Part of the Power in the complete Apparent Power figure is the True Power [the wattage], the remainder is the Reactive Power [VAR].
I rambled all this baloney to you so you would understand the differences in ratings.
Best to get name plate ratings of FLA [Full Load Amperes] from the Equipment to be installed, then use these ratings in your load calcs.
Your load calcs will need to be done as would be figured on any new service.
You will not have too much to rely on from the existing load calcs, since this T.I. consists of a new type of occupant. If you were simply adding more to the existing shoe store, then the original load calcs and demands could be implemented.
Take note of Load Calc descriptions in NEC Article 220, then see the examples given in the back of the code book [Appendix D].
This is as much help I can possibly pass on - outside of doing the calcs myself!
If you have experience with Spreadsheets - such as Lotus 1,2,3 or Excel, you can create a quick and dirty spreadsheet for Load Calcs, then fill it out and print it for Utility Engineers and the Building Department / Electrical Inspector.
I wouldn't see any way this project could have gone through plancheck without some type of load schedule! Be it a NEC type load calculation form, panel schedules, or both.
Let me know if you have questions or comments.