No, your customers can use your menu card via their smartphones or tablets webbrowser
If you host your domain with us then MENUi can be easily integrated. Otherwise a subdomain of your site is doing also the job.
No problem, we can make a landingpage like this and include MENUi into it.
As a result of that your menu card is later included in your homepage, through a link called: www.yourbusinessname.com/menu or whatever name you like for your menu card. Additionally you can put beermats on your table which include an QR-Code that your customers can get there very easily through their smartphones camera.
Yes, of course. Your menu card is acting like an app within your customers browser. When your customers are loading the site the very first time, they schould be prompted to save the webapp on android phones. Otherwise for customers who are on iOS systems have to save it manually with the "add to homescreen function".