Look and feel of my bot "OsteoBot" on my website

Hi, this is my website: www.osteopathy.eu
I have 4 questions:

It's very irritating that the bot keeps on popping up on every webpage. It would be great that once the bot has been clicked away, he stays away until the moment somebody clicks on the bot's icon.
The bot is too big. He covers too much of every webpage. How can I scale this?
Right now the icon is the logo of my organization. I want it to be the icon people see when they chat with my bot.
Please remove "Powered by Snatchbot"

Kind regards,
Greg