Hi 
I'm writing this and can't remember all the points you asked about lol but..
I started potty training my eldest when she started showing signs of knowing she was about to go toilet in her nappy or communicating it to me in some way.
I didn't do day and night together but that was just my choice, like you said some people do. I waited until she was dry during the day before tackling nights but every child is different and some will be dry over night others may take a few weeks before getting the hang of it.
Also, she hated the big girls toilet, even with a Minnie Mouse seat, she refused to go near it so I had potties for a while. If it helps, I had one potty downstairs and one next to her bed so when I started the nights, when I went to bed id go in wake her up to quickly go on the potty then she'd go back off and would usually be dry in the morning. (Also I cut out drinks after 6ish)
My youngest is 17months but is already noticing sometimes when she needs to go so I've bought a potty just to get her used to the idea of it. She's used it a few times and that's when I've left her running round naked as I think they can get confused with pull ups or knickers at the beginning and think it's a nappy so it's ok to do it! Lol.
One more thing which you may already know, make a big deal out of every time they go on the potty, make a little song up or a little celebration dance. They thrive off of praise and i think it helped cheering them on and making a fuss whenever they went on the potty.
Good luck with it all though
sorry for the essay! Ha x