interpretation of conduit vs raceway wet location vs outdoor vs NM NM-B
Yes, that conduit counts as a wet location

All raceways in wet locations are considered to be wet on the inside as per NEC 300.9:


  300.9 Raceways in Wet Locations Abovegrade. Where
  raceways are installed in wet locations abovegrade, the interior
  of these raceways shall be considered to be a wet location.
  Insulated conductors and cables installed in raceways in wet
  locations abovegrade shall comply with 310.10(C).


This means that the answers to your questions are, in turn:

a) Conduit is a kind of raceway (see the definition of "conduit" in Art. 100) (there are also surface raceways)

b) You will still get condensation in the raceways even if the joints are sealed by solvent welding.  So, you will need to use wet-location-rated wire or cable (not NM!) in the conduit.

c) Drainage does matter -- 314.15 states that boxes and conduit bodies in wet locations must be arranged so that water is not trapped.  It also provides that you can field-fit drainage openings no larger than 1/4" to boxes or conduit bodies in damp or wet locations, or use listed drainage fittings in knockouts for that matter.  Take advantage of this, as drainage is your friend, and so is pressure moderation!

d) NM has a paper separator layer in it that makes it unsuitable for wet locations, period, even if the inner conductors were dual-rated.  In general, stuffing cable down conduit is more annoying than it's worth, so you're better off getting dual-rated (THHN/THWN or XHHW-2) wires of the appropriate gauge and using those instead of a cable.