Few points from long thread.
For commuting mudguards, rack and intergrated lights running of motor controller is only way to go. Rechargeable lights are a pain, just one more thing to takeoff when locking up bike and to charge on regular basis. All of above can be purchased online see
www.bike.discount and fitted later but better if bike comes with them.
Because of your weight I'd go with eMTB drive eg Bosch CX, Yamaha/Gaint, Shimano E8000, Brose. You will need extra torque on big climbs. 500whr battery minimum. Some have larger inframe 650 batteries others dual 370whr. Factory drive 500whr batteries like Bosch powerpack, shimano powerpack and Yamaha have advantage they are easy to source anywhere in world. Something to consider if shipping battery is issue. Bosch and Shimano are easiest come by with Shimano about 20-25% cheaper. Plus they can be removed quickly for charging.
Go for higher spec level, definitely 100mm air fork for dirt/fire road riding, as bonus drive train will be better spec. If 10 spd you want 11-42t cassette not 11-36t that are on some bikes, 11spds will be 11-42t or 11-46t. You will need the low gearing when going off road, other plus allows you climb in lower power level extending battery range.
A hardtail eMTB or trekking bike with 29" wheels, they roll better than 27.5. There are 27.5+ wheels but hard find trekking bike setup with them, plus full mudguards hard come by.
Most important thing, do lots of test rides and make sure you choose frame that works for you even motor isn't you first choice. If frame is poor fit you wont be riding it far.