I don't even see what the confusion about the flying Hive Tyrants is. You can Choose to Have wings you don't lose a set of arms is correct that is because it is an Optional Upgrade that specifically says you can take one of these. You can take wings as long as you do not take any of the other options your only allowed to choose one from. Example: Can't have Armoured Shell and Wings.
So Yes if you do that you have a 255 point Hive Tyrant with wings, bonesword/lashwhip, and a Heavy Venom Cannon and its tournament legal.
Next: This is a question that revolves around grammar, and depending on its interpretation determines a squad of Warrior's equipment. A Tyranid Warrior's equipment options state:
"One Tyranid Warrior in the brood may exchange its devourer for a venom cannon."
The next line states: "
The entire brood may exchange its devourers for Deathspitters, etc."
Upon asking Battlegrounds tournament judges, they ruled that it is not legal to run a brood of Warriors equipped with Deathspitters and one venom cannon. I disagree with this ruling completely. Grammatically, if this ruling were true, the rule must be rewritten to say:
"The entire brood MUST exchange its devourers" for Deathspitters, etc, and there would need to be a separate rule excluding the option of a venom cannon if Deathspitters or another gun is taken.
The way I interpret "The entire brood may exchange its devourers" means that the entire squad has the option of exchanging its equipment, but that the entire squads equipment does not need to be universal (entirely one gun).
This interpretation is incredibly important due to the bonesword pack release, where it should be possible to have warriors with boneswords, deathspitters, and a venom cannon all in the same squad.
To back up my claim: The codex itself visually depicts a squad of warriors with both Deathspitters AND a venom cannon in the same squad. (PG 78, bottom right squad) If this equipment is ineligible, the game creators are falsely advertising equipment selections.
Next: Army builder allows you field warriors equipped with dual Boneswords, wielding Deathspitters simultaneously, with one warrior in the squad with a Venom Cannon and bonesword pair.
I'm willing to fight this rule fix all the way to GW.
I'm not a judge and so this holds no weight but this is kinda insulting and an unsportsmanlike Jab at the tournament judges.
The rule in the book as you put it
The entire brood may exchange its devourers for:
Rending Claws Free
Spinefists Free
Deathspitters 5 Points Per Model
An Additional Set of Scything Talons Free
All the mumbo Jumbo you put up there is more confusing because let me point out how they did the
Grey Knights Close Combat Weapons.
Any model may replace his Nemesis Force Sword with any of the following:
Nemesis Force Halberd or Daemon Hammer Free
A Pair of Nemesis Force Falchions 5 Points
This would say let you put in 2 Halberds a Daemon Hammer and 2 Force Swords.
Yours specifically points out that the entire squad if they want Deathspitters must exchange Devourers and cost 5 points more per a model.
I don't have page 78 or 79 in the PDF I am looking at right now its missing in every PDF I have looked at but its probably there in the Hard Copy you have in your hands so I will point out another photo with a Squad of Tyranid Warriors that you Can Not build in Army Builder but they have a picture of is on page 68 at the Top they have a set of 3 Tyranid warriors one with Rending Claws, one with Deathspitter, and one with a Devourer. The photos are more of a Graphical viewing of how they look Put together and Painted than to clarify rules. Again I don't have page 78 in front of me so I can't tell what type of picture it is.
Games Workshop has not posted anything in the Tyranid FAQ concerning Tyranid Warriors and Upgrades so It is left to the Judges at each Tournament to judge accordingly. The Judges at Battlegrounds also consult the INAT Faq for rulings not clarified in the GW Faqs but nothing is specified in there either.
Army Builder itself is not Supported by Games workshop and is produced by Lone Wolf Development. And even then THEY don't make the Warhammer 40k Module for Army Builder that is handled by
http://www.ab40k.org/ who are constantly updating and changing stuff in the Module but even then things they put in are wrong.
Example: If you put a Thunderfire Cannon in a Space Marine army and look at the Army List they print the ruling stated that hits are randomly rolled between gun and Crew. Army Builder states on a 1-4 Crew is Hit on a 5-6 gun is hit. If you look at the Rule book on page 55 its the Opposite on 1-4 the Gun is hit and on a 5-6 the Crew is hit.
Army Builder has flaws and this is why Lists must be Double Checked and Brought to tournaments with your codex and the rulebook and then any arguments after that are decided by the judges.