I appreciate that you've put some time and thought into this theorycraft, any love going towards fiora is welcomed.
I really do understand the impulse to put as much damage on her as possible, and I do it sometimes as a fun cheese off build when I'm messing around, but it's just not efficient.
You have to take a look at individual kit interactions when deciding what items are good on fiora, and then you have to look at what your item build currently has, what it lacks, and which item would next best fit a need.
Lets go over some examples: 
is a sexy item, it has a lot of ad, boosts crit damage, and has crit chance. However, you quickly run into a practical problem when building crit chance items on fiora in that, A) you aren't auto attacking all that often compared to an adc or a yi so you have few chances to proc a crit, but most importanly B) E CANNOT crit on the first hit EVER, and it will ALWAYS crit on the second hit.
This means that a significant amount of your auto attacks (the ones using e) are never going to even take crit chance into consideration - which makes critical chance a very inefficient stat. That's not even getting into the pseudo random algorithm Riot uses for crit chance which makes crits less likely after you crit and more likely after you fail to crit, which would mean that using you e just makes it even less likely that you'll crit on non e attacks. Also, your q does not proc either of your e attacks, not can it crit at all. Which means that the vast majority of your attacks (q and e empowered autos.. and probably hydra active) will completely ignore any crit chance you buy, and in fact make the few other autos you hit with less likely to crit than normal.
Considering how expensive is, the fact that your kit makes it even less efficient then normal makes the item very unattractive for its price. The same goes for 
which includes crit chance and attack speed. Despite the sexy active and flat armor pen, crit is inefficient on fiora and for similar reasons so is attack speed. Attack speed will not greatly help you take towers faster either unless you stack it, while stacking attack speed will not increase your pvp damage meaningfully since, again, you'll be spamming q (which is on a 2 second cooldown late game if you have cdr and aren't missing), e, and waiting out a riposte far fr more often then you'll be in position to freely auto attack someone.
is not very useful because you spend a significant portion of the gold on the mana sustain, and you don't actually need the mana sustain - on top of it just being a rather inefficient item in general that noone buys for good reason.
It's true that by stacking damage and armor pen you can do almost true damage to targets for a short time until you get blown up - or you can build tanky with some damage items and deal true damage through your passive for a significantly longer period of time, and actually live long enough to benifit from your own ult heal - which still heals for almost 1000 over its duration even if you built full tank and no damage at all.
. This build makes you tanky enough to fight long enough to proc your passive over and over and has great sustain from hydra+passive+ult heal+spirit visage, has 40% cdr to spam your spells super often and stick to enemies plus the phage move boost from black cleaver and the burst+slow field from iceborn makes it easier to chase and get into position for vitals. I also go 9/21 for masteries.
and just say what other items could be better than pointing out continuous negatives. Another suggestion you could've made is replacing 
and 
or 
.