I agree with Jongware, it's not that hard, and also there are more than one way to skin a kat:
I don't think I would assign the remaining properties "individually" from the script... I'd rather make an object style manually, with the fill and vertical alignment set, and in that object style I would also set the paragraph style to use (in the paragraph style, font face, size, justification, and other properties are set).
In this way you can change almost everything from the styles.
Using nested styles in the paragraph styles you can achieve lots of things, if you need to have different styles on the header and the body text in every textframe, for example.
You could make a template document that contains the styles, and have the script open that one instead of creating a completely new empty document.
(Or if you refer to activeDocument from the script, you just add the styles to your document.)
With the styles on place you could let the script assign the object style, using a single line as below:
newTextFrame.appliedObjectStyle = myDoc.objectStyles.item('TheNelsonStyle'); // ...or whatever name you decide for the object style ; -)
Always try to make use of styles! At least they usually tend to save you from more trouble than one cause by not using them!
Good luck!
Andreas Jansson