General Scale and Length Factor in drawing preferences

In the Drawing Preferences there is General Scale and Length Factor.

I want to draw a scaled object.  Have been using a General Scale of 1
 and a Length Factor of 3.5.  Is this the standard way of drawing a
 scaled object?  

The downside of using Length Factor is that I have to convert my object
 measurements by 3.5 before starting the drawing.  Doing so makes the  
 dimensions to be printed at the actual length of the object.

The standard way is to set the General Scale to the reciprocal value of the planned printing scale. So for scale 1:10 it is 10. This sets the dimensions text etc appropriate for the scale. You can leave them at the standard setting for any scale.
With Length Factor you can manipulate the reading of the dimension, but the part stays the same size. Of course you can achieve a right looking drawing this way, but it is inconvenient.
Normal it is to draw with real world measurements, leave Length Factor at 1 and do the scaling down in the print process, in Print Preview.

If I draw with real world measurements, how does the Paper Size affect things?
The paper has a fixed size, would it not be too small for the drawing?

As I said, it is scaled down for printing so it fits on the paper size. It is best to consider in advance which scale is needed to fit on the paper. Scaling then is done in Print Preview mode. Also if you only want to export to pdf.

I understand.  But I also want to have a Title Block.  Would I have to scale that up as well?

Yes. If for instance you decide to print at scale 1:3.5 (as you wrote) then you have to draw the title block and page border 3.5 times larger as intended on paper. During printing it will be scaled down together with the drawing content again.