Why does this game hide essential character info?

[wdeschain]

I've subbed 4+ years.I am here after wanting to understand stats better for tanks--my PLD--WOW! What's crazy to me is that I really never thought much about the stats because, as mentioned, player created content always was available .A couple weeks ago, I was re-reading the short stat narratives, and questions popped up that I've thought about many times, yet never sought answers.

OP, I applaud your post--more players should herald the observation. I'd like to add to OP's outspokenness my reoccurring boggle throughout my subscription tenure. I am tired--and apologize if I like clarity..

On our character UI window we have an operational button with the ability to equip a personal inventory BiS.
1. Is SE algorithm correct? Have we merely been duped by a covert organization that has purposely distorted stat weights so as to retain ownership of the ranking on the site that shall not be named? Seriously, who is correct: a) SE Devs OR b) FFXIV content creator X?

2. Why would the above mentioned BiS in-game tool NOT fit us with BiS? Is it that content creators engines churn out gear sets that focus solely on maximum damage output? --while SE's calc does some function that adds job specific variable to its equation (e.g. piety, tennacity)?

3. I have experienced this with crafted HQ versus patch raid gear versus tomestone. All MAIN STATS equal--the only difference being "sub stats." The following is merely one recount as it's the freshest in my mind. I outfit pld with 350 norm gear. 5.05 begins, and so with my avatar, I penat-meld HQ acc's(neck & a ring) plus penta up a chest and leg slot. I manually equip the penta-melded, replacing the norm 350. If i go to the in-game BiS solver, it wants to put the norm gear back onto my character. I ignore it. I have been omni thru SB, and so I glam alot. That said, I use the BiS solver often as a quick check to make sure I'm not slotting any ilv 1 pieces I was glam geeking on. I have seen the norm pieces from want to take the slots over my pentas though they haven't been worn for a few instances. THEN! Magically! The BiS solver no longer wants to place them on my avatar--I sure hope someone else has witnessed this!
Why does this happen? What is going on?

4. FFXIV demands that X amount of dps be doled out on X boss in X amount of time or you will be served an enrage.The dps pld skills have tooltips that contain their potency, and this allows me to craft a rotation without player created guides(yes,I know...pld is on the simpler side) Stats that affect the effect of my dps in any given instance are an unknown--though absolutely necessary to aid a party in taking down a boss under SE's fight formula of partyDPS>(Boss HP/Instance Enrage Timersecs .
I am a bit tired, but please do not read as salty. The OP has a very legitimate question.I hope it entices converstion and a SE response. Peace.