I'd not worry too much about it vskid3, Giants are fine bicycles & the charm of the hub drives is they're so easy to transfer over to another should you later decide to change. It irks me to say this, but v-brakes do work perfectly well - if stopping power is insufficient, better pads can be had.
I dislike them for other reasons, perhaps not as applicable to a first ebike experiment - persistent maladjustment, long term rim wear, wet conditions, ice & snow pack. As a year-round daily rider/commuter these take precedence but for you, perhaps not so much if all you wish is to stop in a timely fashion lol
If budget is a concern, I'd spend the difference in better/larger batteries then switch the Giant to disk as smaller upgrades like that can come later.
The half-price ebay "no name" drives can be a good deal, again LiFePO4 batteries the critical & expensive bit - but as you prolly well know, with generic ebay stuff "you buy your ticket, you take your chance" & hope for the best... I did so w/my hybrid taddy's drive as it's MP2 usurped & on another bike (s'posed to be just testing, couldn't bear to take it back off Mongo lol) and it's been... good enough
