No you don't. That's my case too. I have some millions pageviews per month. Most of my sites are info sites.
I don't think the smaller hosts have the same level of dedicated security expertise of the larger hosts.
Exactly. I took an advice and went with HostGator since day 1. They are one of biggest. Their technical support is super.
Another advice: Don't think SEO, think about the user. Never add content to the Internet unless you absolutely sure that it is unique, helpful and better than anything out there. If it's not good for the reader, it definitely won't be good for you SE ranking.