Admin Pages and Dynamic Options

I’ve searched around for an answer to this, but haven’t found anything very useful. Apologies if this has been asked before.

I’m trying to convert some shortcodes to a more user-friendly options page. Basically, I want the user to be able to edit all of the data/settings through an options page in the Dashboard.

I’ve got a pretty good handle on basic options pages, but I’m running into problems with making the settings dynamic. For example, I need the user to be able to create new content “blocks” through the options page. As a result, I won’t always know how many blocks there are (if any), so I can’t just hard-code the options in with the standard Settings API.

My solution is to pretty much circumvent the Settings API and retrieve the data manually with $_POST. Then I can build an array as I like and update the options using the update_options function.

My question is 2 parts:

1) Is there a way, using the standard Settings API, to generate dynamic options?
2) If not, what are the implications of doing everything manually through $_POST (e.g. security, compatibility, etc.)?

Hopefully that makes some kind of sense, and thanks in advance!

EDIT: It appears I accidentally posted this in the main plugin forum, rather than the Hacks forum. Sorry!