You can crush on someone based on their appearance, but I'd say its a much more superficial crush than a crush on someone whose personality you know.
When you say they "look like your type (personality based on their physical appearance)", you're just projecting what you THINK or WANT that person to be like on them. It's not representative of who they actually are. You're just crushing on the person they are in your imagination.
I don't believe you can love someone without actually knowing them.
"if someone seems interested in you although you never talked before or know each other then do you assume they just like you based on your physical appearnance?"
No, the erson might know thingns about you before talking to you
You can have a crush or lust for someone based solely on looks. You cannot fall in love with someone based only on appearances (though some people think their lust is actually love and will call it that)
I love my girls tall and skinny! Yes I've fallen in love with one and once I started talking to her I fell in love with her even more, she really had the sweetest and caring personality and had the most incredibly skinny ass lol hot.