I'm hoping for some help here.. google SERP has been very inconsistent the last few months, and I'm trying to figure out if there is any perceived "duplicate content". I also want to improve the ranking for products, I have some very good (unique) info on those pages.

In robots.txt, I have restricted the following:
Disallow: /reviews.php
Disallow: /review/

When I look at site:domain.com, the first listings (under the home page) are the following:
/category/
/merchant/

I also see links to search.php (these would be from some main menu links), and products.php (even though i've since enabled the mod_rewrite, probly just old)

Do you think it would be safe to tell robots.txt to restrict any of these..? Or can I tell G to prioritize /product/ in the sitemap..?

Any help much appreciated, I'm really lost why my site keeps dropping

Thanks!