If a bot hits your site and you don't give it rules
(robots.txt), you can pretty much assume it will index everything it sees.
The submissions, done manually, or via cpanel are just invitations to come crawl and a "map"(
url) to your site. Without the invitation they will eventually find you anyway, after all it's their job, and they are only dumb, untiring bots. If you want to see if they've been there just look in stats in your cpanel; I like to check for them using awstats, but that is just a preference.
I am no expert in SE, that's why I supplied the link, but they each have thier own rules of behavior (that change). Research is needed to discover what each bot may or may not do specifically when they find your site.
Some links that describe some of the SE spiders and how they behave
(what they will index - will they come without submission):
InfoseekAtavistaLycosExciteWebcrawlerGoogleNorthern Lightand Vanya did answer your question regarding will they index without submission
QUOTE
Your site is indexable by search engines.