I want to reiterate what has already been said; this does not feel like Excel. If you spend some time watching (medium-to-low skill) people who use Excel as a general purpose tool to perform general tracking and calculation tasks, you'll see there's a very different way they work.
They start with a blank sheet, and start putting data in rows. Then they add some formulas to the rows, and do a bunch of sums on some columns. The idiom you've chosen, of dragging and dropping, is a significant workflow change.
A few more things that I haven't seen pointed out already.
Your pricing scheme should differentiate between designer and non-designer users. If I buy a personal account, it's kinda useless when I can't give my url to someone and tell them to create a new entry and edit data.
Also regarding users, the lack of OpenID integration seems an obvious lack. Creating an account just to enter some data is a pretty high bar. Ideally, I should be able to share a form via email, implicitly granting data entry permissions to the recipient, then they can click the link in the email and be prompted to use their email provider's OpenID to authenticate.
Anyway, you've got some good ideas here, but I don't think you've got the right focus on Excel/Access users quite yet. It lacks the feel of Excel, and lacks the features of Access.
If the user already have data on an Excel, we provide an import wizard so that they can import their Excel and create a database with it.
If the user does not have existing data from Excel, they can first define the data fields on Ragic using the design mode. They can actually create cells as fields just like they would on a spreadsheet, but a lot of users find it hard to catch on so we added the drag and drop model just recently. So both ways should work okay.
And actually we do support OpenID log in, and the ability to click on an URL in e-mail to grant access to some DB entries. I guess we have to work on making these features more obvious to users.