The flowers may be male since cucumbers have sexual distinct flowers i.e. either male or female!Climatic or nutrient deficiencies can also result in flower abortion prior to or after pollination.
Not really. Even though there are different cultivars of cucumbers, there really is no difference between a "normal" cucumber and an "English" cucumber.
Yes, but the seeds found in supermarket cucumbers are immature (otherwise cucumbers would be full of chewy seeds). Immature seeds will not grow, but cucumber seeds are sold (fully mature) in most...