How do you set a field to accept more than 1 line? filling in a paragraph of text without having to TAB between each line?

If the underlying page has lines, there isn't a setting for multiline text fields that let you specify the leading to match the spacing of the lines. But you can set up the field so that the lines are only visible when the field is blank, since they are really only useful if the form is printed and filled-in by hand. Here's a link to a sample form that demonstrates this approach: http://acroscript.net/pdf/demos/multiLine_Demo1.pdf

Be sure to download it since it doesn't work as intended in Chrome, Firefox and other built-in PDF viewers.

Tick the "Multiline" box under the field's Properties, Options tab.