Does a cursive-font-generated signature carry any legal weight?
On its own, it does not establish verifiable identity or consent, because it lacks certification, an audit trail and a cryptographic link to the document; its value is aesthetic, so any use where the signer identity needs to be proven requires a recognized electronic signature mechanism, not just cursive text.
What is the difference between this visual signature and a certified electronic signature?
A certified electronic signature, such as one using an ICP-Brasil certificate, binds the signer identity and the moment of signing to the document through verifiable cryptography; a font-generated cursive text only reproduces the look of a handwritten signature, with none of those verification elements behind it.
Can I use this visual signature on a business card or personal logo?
Yes, and that is exactly the kind of decorative use where the cursive stroke works well: personal branding, stationery, an email footer, or a design piece where there is no requirement to prove identity to a third party.
Is there any way to make this visual signature legally valid?
The cursive image alone cannot, but it can serve as a visual element inside a real electronic signature workflow, as long as the system used adds certification, signer authentication and an audit trail behind the artwork, because that combination is what establishes legal validity, not the stroke itself.