Yes, it’s normal to get twice the life out of a front compared to a rear tyre. My X-Town did about 5,000 miles on a rear and was on course for 8-10K on the front.
Your car depth gauge is good for the scooter and there should also be 1mm wear bar indicators in the grooves. Personally, I ignore those as I’d change them out at about 3mm. Bikes have only 2 palm size contact patches, I prefer them to be in tip top shape!
As for which brand / type, go with what works for you. I like Michelins, but I don’t think they do enduro type in scooter sizes. That’s what I’ll be needing (enduro) for my DTX360 when they need changing, so I’m actively looking ready for then.