I think we have all been where you are...
The first advise I give is to note what changes you make. For example, if you turn the truss one direction 1/8 or 1/4 turn write it down. Turn the nut or saddle by 1/4 turn and write it down. This way you can always go back.
On the NS it is normal to have the slight arch on the bass side. (I once made the mistake of making a visual adjustment of the truss using the bass side and everything went really bad...) I don't think the slight bow in the bass side is due to tension but because of the amount the bass string actually travels in it's vibration. I know on the Railboard (and probably all standard sticks) has a bow carved right into the frets in the middle where the thick bass strings are.
For me it is too hard to adjust the truss by sight so I do it by feel. If I hear or feel that the notes aren't playing right or I hear some buzz or other sounds I will make a slight truss adjustment and it seems to fix it right up. I can't visually see the difference between before and after... but I do see the slight bow on the bass side and straight on the melody side. It can be that I don't have good lighting but I trust the final playability.
From your descriptions it seems like the overall set up of the instrument is good. I would experiment with the truss first. I would start by making 1/8 turn in one direction. Write down the change. How did that change it? Difference in feel? Clacking still there? No Change?
Turn it another 1/8 turn and see how that feels? Usually by a 1/4 turn you will notice a change but it depends on how much your instrument needs adjusting and you may have to go further.
No change? Getting worse? Go the other way.
Adjust is past what you feel is good then take it back to get a feel of what the truss adjustment really does.
From your description it sounds like the instrument was set up correctly. But it's hard to tell without actually seeing it. I think that once you adjust the truss you will notice a considerable improvement. I'm thinking that loosening your truss will fix the issues you are having.
The 1st fret is the hardest fret to play. (In my opinion
) It's a combination of skill and adjustment which will get the most out of it. You can raise the nut and see how that feels. I slightly raised my nut on my bass strings but I still have to concentrate a little harder when playing that fret to get the note right. Practice playing with your left hand and hit fret 1 through 4 with each finger and work to get the same volume/tone on each fret. (This was on Don Schiff's lessons on the NSStickist.com on NS/Stick Tech)(a little side note... I tune my NS/Stick down a half note as I was finding there were many notes I wanted to play on the first fret and having some difficulty. I also want to tap the "open" string note. As a bass player I almost never played an open string and need my left hand. Tuning down a half step essentially makes the first fret the "X" fret. I almost wish the NS was made with an X fret and some kind of capo system for "open" tuning.... just my thought.)
DON'T FORGET.... you will probably have to adjust your intonation...
Good Luck!
