Dont mention it, Pally, glad to help! Plus I quite liked the mod, so thanks for letting me know about this object, haha. It is indeed better than the official Fruits and Veggie Stand. For the official veggie stand, in order to cancel your consignment items, you have to do it one item at a time, so you're gonna have a bad time if you've consigned 200+ cabbages and decided to take them back.
Yes I did test that while playing around with the stand. I waited until a non-family sim bought something from the stand, a group serving of Lobster Thermidor, I then checked their inventory using Nraas, sure enough, they get the lobster meal in their inventory. The description in the mod page tells us that everytime a sim buy something from the stand, an item from the stand is randomly selected and bought.
As for your second question, it looks like the active family is always able to give commands to the stand, change ownership, tend stand, add/remove items etc. The only thing you cant do is taking and putting the stand into your inventory, since you are not the original owner of the stand. All the settings of the stand is preserved when you switch active family. I switched my family to the Wan family and the stand is still tended by Agnes, all items are still in the stand inventory and profits still go to my previous family, until you change the settings.
You can also lay some items on the stand like a table, those items will not be bought, it looks better this way. Otherwise the sims look like they are browsing and buying from an empty stand and that is just freaky.
Lastly, the mod files need to be renamed so that you can properly recombine them. For example:
MTS_ani_OFBStandFixed210913.part1.rar
MTS_ani_OFBStandFixed210913.part2.rar
MTS_ani_OFBStandFixed210913.part3.rar
Happy simming!