2. I am assuming that the positive and negative are refering to back
rake.
--------Yes, except as the rake is modified by grooves and such on the
top face.

3...., 3.5..., 4....
--------Typically true.

5. Why does everyone want zero back rake?
----------For edge strength.

6. I found a source suggesting using a TNMP insert. I think that this insert has chip breakers on both sides so it
could be turned over and used again. DOes anyone know for sure? I
think that this is the best way to go. Has anyone tried this?
----------You can use TNMPs on both sides. I like TNMGs better than
TNMPs, but I have a stout lathe. I find it hard to get chips to break
with TNMPs.

7. What effect does the tip radius have. I beleive that the larger
the raduis the smoother the surface finish on turned work. However,
the larger the radius the more power required.
-----------Big tip radius is bad for a lathe like yours. You'll get
chatter and pushback from the work.
Any help would be greatly appreciated. Thank You

--------I suggest trying some of the Rouse or Borite screw-down sets
that MSC, ENCO & others sell. These use TCMM, TT221, or TPMT or
similar inserts. The trick is to get good quality, name-brand inserts
like Kennametal, Carboloy, Iscar, Valenite, Sumitomo, etc. Another
approach is to get one of Circle Machine Co's square shank holders
that lets you use their boring inserts for outside turning. Their
stuff is pricey but can be found on ebay. The edges are typically
very sharp, nose radii are small, and they sell carbide grades
specifically for low surface speeds. Carbide likes to run at 250
ft/min surface speed and higher, but you will have a very tough time
doing this with your lathe.