es330td wrote:
For a homebuilt, is builder status conferred on the person who buys
the kit/plans and starts it or if I buy a partially built plane and do
the rest am I now the builder of the plane?

FAA Advisory Circular AC 20-27F "Certification and Operation of
Amateur-Built Aircraft" should address that and some of your other
questions - you may want to review it since it discusses the paperwork
angle and steps needed for certification. It is online he

http://www1.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/0ca2845e2aafffbb86256dbf00640cb2/$FILE/AC20-27F.pdf

There may be multiple builders, but only one of the builders can get the
repairman's certificate for that aircraft: the "primary builder" who can
prove to the FAA that they know how to determine whether the aircraft is
in a condition for safe operation. The repairman certificate merely adds
annual condition inspection to your list of privileges.