My advice would be not to over think things. Buy a bike that feels comfortable and start riding. Each bike has its own pluses or minuses but what's right for me may not be right for you.

I also don't think you should over spend or stretch your budget. The majority of bikes sold seem to be ridden only a few times and end up sitting in the garage. Also, you want enough money left over for essentials like a good lock, proper clothing, & probably some lights. After that a rack & panniers are usually a good investment as it adds more functionality to the bike

The only real secret about riding in the road is acting like you belong there. Be visible & be predictable and things should be fine.