Like all things relating to people, it varies.

Some women actually prefer smaller penises. A friend of mine was that way - her ex husband was too big for her and sex hurt. Her next husband was smaller and she discovered that sex could be enjoyable for her, too.

Some like 'em big. And some don't care.

Except in extreme cases, it's generally not a deal breaker and usually not the most important factor for enjoyment. My girlfriend likes 'em big but her ex husband was well below average. He had skills, though, so she had no complaints (in regards to the sex, anyway).

As far as oral sex goes, you've been misinformed. Lots of women like to receive oral sex.