Not a teen, but I would definitely get an e-bike if I could just to get around my city. Especially since the places I would actually end up going aren't too far away and I don't go many places.
Only problem would be winter since I do not handle cold weather all too well.
From someone who rides his bicycle year round even in very cold weather (sub 0 degrees Celsius): Scarf, not to warm jacket, gloves is all you need (and what you will probably already wear in winter).
Cycling keeps you warm, you don't need much equipment against the cold.
That depends on how much power you are putting into it yourself versus what you have the battery add. On flat surfaces with no wind, I ride my eBike just like a normal bike with no power from the battery. Uphill into the wind? Yeah the battery is going to help me.
High pedal assist to minimize pedalling and maximize breeze. I had a summer internship where I commuted an hour each way on an ebike, even on hot and humid days like that. Honestly, I wasn't that sweaty by the end of it, as the breeze and pedal assist work wonders for keeping you cool.
How much of the year is the weather too bad for you to ride? 4? 6?
I ride my ebike almost every day of the year, winter included. It does get pretty cold here for about 4 months, but we don't get too much snow/ice. That said, even if the weather was too crappy to ride for 4 months of the year, that's still 8 months of the year that I can ride the bike, so very much worth the investment for me.