xfa.host.appType will return HTML 5 if rendered as HTML, you can test that value and enable the appropriate signature type

signaturefieldname.rawValue = "";

You can not run an XDP on an iPad, currently you need a server to render it to HTML5

I'm not sure I understand but this is what I think you wantrow 1row 2row 3row 4row 5The user may click row 3, then row 1, then row 5 and you want them to come in the following order for the other elements you're adding with instancemanagershow 1show 3show 5Is that what you're asking?

This is confusing you mention at the beginning that you have a licensed version of ES2 Designer. I'm guessing the installation was lost somehow. If you qualify for an upgrade Upgrade Adobe Designer | Acrobat XI then I don't see an issue with using the trial. Also if you have purchase the ES4 Designer and are just awaiting delivery then this is fine as well.

If that's the case your form won't work for people that are visually impaired

In Designer select the mandatory field, open the script editor, pick the exit event, and enter yourfieldname.access = "" surrounded in an if statement to check if the mandatory field is empty. I'll email you a small sample

You're in the Mobile Forms forum here not Lightroom, you might want to try asking your questions here Photoshop Lightroom

You would have to use LiveCycle to render the form as HTML5 for use on the iPad