I noticed a very small amount of oil seeping from Oil Pipe B where the pipe connects to the rubber preformed hose that goes to the oil tank. (Right side of the bike.) I tried to clamp the hose and it reduced the leak but there is still some seeping through 500+ miles ride and just a few drops. My first thought is to just replace the preformed rubber hose ($82+ shipping) but does it make sense to replace Oil Pipe B ($60 with o rings + Shipping) as well?

Also, the connection between the rubber preformed hose and the oil pipe does not have any sort of clamp in the microfiche. is this a mistake or is friction enough?

What bike are you talking about and I assume you tried to load a picture?
Pictures can't be uploaded you need to link them from Photobucket or similar.
Paste the link in your post.

990 superduke 2007

Any leak I had on my 990 was successfully fixed by replacing the rubbish original clamps with some quality stainless ones.
If the hose is not cracked try a good clamp first. If it's been overclamped or you see damage in any way replace.
Any oil proof hose form a car shop will do as long as it's the correct diameter and the shape fits.
Also make sure the cap is properly on the oil tanks as they tend to leak if not done up properly and the wind blast blows it all over the place when riding.

as guy said and check the plastic sight gauge hasnt got a split in it too

OE pipe B and hose doesn't have clamp, appears to be heat shrink fit or similar - it's a pita to replace without removing battery box, oil tank and front header so suggest s/s clamps and both ends of hose/pipe connection if there's space behind engine hanger (may have to reroute +ve and -ve cables to starter motor).