Problems with search module

Problems with search module

Several questions 
- i can't figure out what's the purpose of the drop down in the main top search field (category and location) 
When entering a keyword , in wich field does it search ?
Anyway, whatever the drop down selection, i always get an error 500 if seardching for keyword
- Wouldn't it be logical when using the location dropdown at the bottom of the module without entering a keyword that it return all location related to this search , instead, it returns an empty page 
- When doing a radius search around a city, wouldn't it be logical that this city appears first in the result list ? 
Thanks