Suzuki,
Carbon fiber is tough stuff..if Reeve would choose a material to compliment a "work" knife's other handle side of Titanium, you should not be concerned about any normal use, whatsoever.
Things used, get scratched..don't be afraid.
Concerning S35, and using as you have described, I use mine regularly for whittling etc and it does fine. I really don't see any noticable difference between it and the prior S30v Sebs I've had, in either edge retention, or ease of sharpening.
Concerning contact with hooks etc..steel hitting steel, or steel hitting bone will always have ramifications eventually; dings/flat spots are part of the game, especially depending on the amount of pressure used in cuts on surfaces like that, but if you have a wire edge..it will show up more quickly
If the knife gets wet, does it need a full cleaning or just a rinse an dry? And does the pivot tend to loosen? Is the tip strong? When I got my military that was a concern o mine because of the thin tip
I have gutted many fish and deer with a Seb and never took it completely apart afterwards..Just rinsed it, dried it and when I got home made sure that I got any extra debri I might have missed out of the way when I oiled it..same as any other knife...You might just keep an old toothbrush, or some quetips in your fishing kit to help in the field if it makes you feel better to get stuff out of the way before it dries..(after I have skinned deer, I've just used a twig to get the gunk out of way before I closed it) again, same as any other folder with this exception..consider how tight the tolerances are on your Seb, especially around the blade and pivot..you would have to have a lot of prolonged cutting on fish before I would begin to worry about debri being any place other than the exterior of where the blade rotates on the pivot,..your $ paid..did have benifits for these applications

.
Keep in mind that folders have issues fixed blades don't in these applications; If you are skinning a lot of fish, for example, your blade will have gunk collect around any open areas/gaps between moving parts, or handles, that's why you should consider how you want to address that..much easier before it dries, imho.
The tip is thin, but that's a plus with dealing with fish, or any penetrating push cut..
I have yet to have had a pivot loosen unless after prolonged use over years of time..but again, easy fix with the supplied wrench from CRK, if it does.
Understanding your concern after dropping that kind of $ on a knife, and wanting to take care of it, just want to help put your mind at ease by saying Sebs are tanks. All mine have been through the gauntlet of normal uses, but glad to let you know there has been no blade play...no issues..no warranty claims..nothing resulting from those uses but thankfulness and highest recommendations for others to enjoy what they worked so hard to purchase.
In closing, so glad to tell you, that you have the tightest tolerances on a production knife in your possession....The Sebenza is a work knife...use it happily & don't baby it :thumbup:.