The thing to remember when creating tags is to set you text height 1/6 the size you want it in the drawing. For example if you want your text to be 6" at 1/4"=1'0" scale then create the tag with the text at 1".
As for the text style, check what buzz suggests, but also look at the properties of the tag on your palette and make sure the attribute text style is set at "As defined by content" (see attached).
Lastly, I'm not a big fan of adding property sets to the template. Personally, I let the tag, schedule, label, etc add the property set when I use them. You can also create a dummy tag that will only add the property set and not any text.
The reason I do this is that have a lot of property sets, schedules, and labels and use them depending on the type of drawing I'm creating and don't want to burden my template with all of this information when I may only need 10% of it.
Since I'm not a mechanical guy I'm not quite sure what you're asking in the last paragraph. If you can post an example of what you want I may be able to help you with a solution.
Hope this helps,