Again, Wordpress and Frontpage are two different animals. Frontpage is an HTML editor / web design program. Wordpress is a blogging platform. So neither of them is going to have all of the features as the other. Though they both have similar functions - to publish content.
Someone might use Wordpress instead of Frontpage if they wanted to update their site daily with new content or journal entries. If your pages will not change often, a static website designed in Frontpage (or any editor) would work fine.
Wordpress wont 'compromise' your SEO efforts. You will optimize your site basically the same no matter what CMS (content management system) you use to design/maintain it.
If you already know Frontpage well, why are you considering using Wordpress?
Blogging is used when you want to constantly publish new content on a topic, and is a great marketing tool alongside a website in almost any niche. It helps you to build a readership in a niche market, and you can funnel that traffic to your offers (sites).