Armor penalty for a chain shirt is only -2, and the build includes stealthy feat giving +2 due to have a lot of extra feat from being a fighter. So zero overall armor penalty. The same a Dex build in leather. So your arguments are moot.
Will a pure dex build be better at sneaking. On paper yes, but in practice it's irrelevant as they will both exceed the threshold for most enemies in all the NWN campaigns.
The build is wasting a feat on Stealthy (and one could argue Iron Will as well). It gains you nothing. +2 sneak isn't going to make or break the build. A DEX based Rogue would have significant advantages while sneaking over a STR based one so you don't need to try and "make up the difference". That feat would be better placed almost anywhere else - like Toughness, Blind Fight etc.
Basically, as a Fighter you are losing out on +5 to all saves and Keen Senses for a little more damage against crit immunes. You also end up with more feats than you need, hence the wasted feats in your plan.
Although the other point you make is valid - a STR based sneaker is very viable and I agree, much better in the long run than a DEX based one. It's unfortunate that NWN 1 never included Epic Precision, because that would change things. A STR based Rogue can actually get a really decent AC with a Large Shield, which only slightly impacts his ability to sneak (again, completely negligible in real terms).
Then why sneak at all? You seems to miss my new position - what am I saying that str character has BETTER choises then sneaking around. Once again its not that you can't do str shadowdancer but that high str fighter/rogue hybrid can take more forward root and not waste time with sneaking. Dropping SD for, for example, Cot will give you better saves, let you get higher str and con. WM (which you can easy get here since you already has few prerequests) will give superior focus and Ki critical.
So no, argument is not moot and it is not about "go dex sneaker". It's about why building str sneaker when you can build simple melee character who would fight as good and in some places even better?
Meh, Peter is right there I think. The advantages are clear - access to all Rogue skills, good melee fighter AND fair sneaker with the addition of loads of extra damage against most enemies. It fills a number of rolls well, where-as a Fighter doesn't do much apart from stand there hitting stuff.
Boots of speed stealth off, run your elf around a dungeon with traps, you will hit them before you see them.
I never had the issue you have with human, because stealth on is enough to slow down to detect traps, there is no need to enable search mode as well. I never use it, never have a problem.
IMO in either case you need High search skill + stealth (to slow down a bit) and you are golden.
If you are walking around in Search mode at half speed, The Elf can do the same while searching AND sneaking at the same speed. There is literally no reason you can tell me that having Keen Senses isn't a plus for any character interested in detecting traps.
Same point I made above. Damage is there for the ubiquitous sneak immune like undead where you will want every point of damage because not only are they sneak immune they often have damage reduction. If you could sneak attack everything, then even strength would be pointless, and all rogues would just be Dex Build sneak attack machines kill all in their path. But it isn't like that. Campaigns are full of sneak immune with DR, so the extra damage from WS/EWS is a big deal.
EWS is a nice feat, sure, but you don't need it here at all. You have STR and you have sneak dice. A standard Fighter needs all he can get since they are a one-trick-pony, this character is not. It does not NEED it. So, I don't agree at all, but I sense where this is going and realise you are not one to take criticism well. My arguing the case here will only fall on deaf ears.
I had a look. Typical Build for level 40 mentality, can't use anything but rogue weapons/armor until Level 11, doesn't get Shadowdancer to Level 21 !
I make my build for maximum play-ability early on. Weapons and Armor from Level 2, SD from level 8. You complain about my build taking Blind Fight at level 12. The same level you take it. ;)
Not at all - I make the builds for 1-40 play (not that that is ever possible). It plays well at low level so you are talking rubbish here. Infact at this point it looks like you are clutching at straws, so as I said above, I will leave it there. If you want to shuffle levels around you can - the level split works, as does lower level play and it is much better as an Elf.
Anyway, I will leave it there. Hope whatever you end up playing works for you.