Is playing through Fort Condor necessary to advance through the

Nope it can be skipped entirely. There are various items you can obtain for helping them fight throughout the game but it's all optional.

>>385661534
I think you have to play it for a story related thing eventually.

I think i failed it once and could progress anyway

They wanted me to get the Huge Materia as i did over in Corel so I'm unsure.

It's mandatory to play through but not mandatory to win. If you lose though you don't get the huge materia and I'm pretty sure no chance to get the Phoenix materia either.

>>385661534
Yes and no.
You can progress through the story no problem.
You can't get the Phoenix materia, though, which means you can't make a Master Summon Materia except for the one you get for beating the Weapons and trading shit to the Kalm traveller.

>>385662053
Those don't affect the story. Even if you get all of them, the rocket attack on Meteor still fails and the story happens the same as if you don't get any of them. Missing the Huge Materia just means that they won't be in Bugenhagen's lab and you won't be able to make Master Materia (all spells on one materia, all summons on one materia, all commands on one materia).

>let enemy reach base
>kill Commander
>win

Effort is for chumps

Theres only one mandatory Fort Condor minigame on Disc 2 during the huge materia quests but you can throw the minigame battle and just fight an easy as fuck boss battle instead and still get the huge materia+phoenix

>>385661534
You can deliberately lose the RTS battle that takes place at Fort Condor and still progress. Winning the fight is only to get the Huge Materia.
You can even lose to the boss that shows up if they get to the peak and it won't be game over, you just won't get the Phoenix Summon.

>>385662693
There is also a way to win the mini-game super quick. If you can make it to the bottom really quick through skillful unit placement and kill the first enemy before any others spawn, it will end the battle.