How to set up Apache Solr with facets so that it uses a front page search form?
Question #1: 
Go to admin/config/search/apachesolr/settings and select 'Bias'.  There you can set up the weights next to the terms you want to search through.  Perhaps they're on 'Omit' or something like that...

Question #2: Go to the search settings page and make Apache solr search be your default search.  That way, when users type in keywords in your regular search form, they will automatically use your apachesolr search.
admin/config/search/settings



Let us know if that worked for you!