Congratulations on your upcoming baby! Bengal kittens especially have a ton of energy! Would it be okay to leave the kitten alone while you are at work. Only if you play with the kitten while you are home and wear the poor little thing out so all it wants to do is sleep! You can purchase a wi-fi camera and be able to watch your kitten through your phone or computer at work.
But, as for going away for more than 10 hours, it is important that you have someone check in on the kitten or have someone look after it at all times. Kittens can get into trouble and find themselves in situations they can't get out of. When you are not home, I would make sure your kitten is limited to the areas it can access in your home. Only because they can find a hole anywhere and get through it. One member thought her kitten had gotten out through a window, then heard it crying behind the kitchen cabinets. One can't watch their kitties 24/7. If you are able to take a few days off work to observe and bond with your baby, that would be great.
There are many bengals trained to use a toilet. The thing is to keep a kitten from ending up IN the toilet and not being able to get back out and, thus, drown! Personally, I prefer having a litter box.