"I just think that its really freaking annoying to deal with nexus from the fort side."
Yeah, certainly is, but I think that's a good thing. It's part of the fort RP dynamic. And though there are some people that think fort should just be about eradicating everything that isn't them and that might someday pose a problem, I never see it that way. I had a hell of a long talk with Puhg for example, after I rolled up my fort bard, about those things.

"It's basically powergaming."
I also don't see it that way. If fort is all about the greater good of the light, and nexus is willing to help you get back your orb and maybe slay a few scions or imperials in the process, I fail to see why it could not be embraced. Take it as an opportunity to preach, to engage them, to try and convert them. It's a golden chance to understand and interact with them. I don't see grouping with people as an act of acceptance, forgiveness or condoning what they do. It's an opportunity, and people make of it what they will. Lots of imperials I grouped with offered me the oath for example.

"while Fort is strictly forbidden from striking back on favorable terms against the Nexus"
I saw some fort people come after us, and yeah, it's not usually favorable to them and may have IC consequences. But, those are the restrictions of the cabal. People throw fits when battle go after non-cabal enmies and non-mages. You have drawbacks in a cabal, and if you ignore the cabal's principles you're going to end up in trouble eventually. In fort, it's not being a zealot against nexus, plain and simple. And so you know, I got summoned & cranialed to death by Athioles and a shaman as I was walking down Eastern. When light had ceased tipping, but I did not tell them that, not that I think they wouldn't have done it anyway. So you can strike back. Maybe not wage all out war is all. I imagine if you know light is tipping, you will not get in as much trouble for being proactive against them.

"Its really more of a question of how Fort can steamroll you back."
Fort can steamroll Nexus, just have to do it the right way. If you know light tips, you know they'll likely come, and a strong defense can effectively tear apart any group. And sometimes, you just have to avoid the fight. Certain people are bad matchups, but Eachainn + Vallinane can effectively beat the hell out of lots of bonded nexus pairs I'd wager.

"fort was sort of that whipping boy you could bring out whenever you were bored "
Hey, I loved me some fort people, and I was rarely overly aggressive against you guys I felt. I even gave Fort a try but I admit the cabal itself is not for me really with my play style, I tend to be a bit more of a run around alone exploring type than anything where Fort seemed like one big happy family. Allysia was a huge exception in terms of my willinginess to PK instead of just leave people alone, I'm about one of the most non-pk oriented players out there I feel like.

I rarely whipped on you guys by the way, that's why I said the PK numbers. They are more of an example of how rarely I personally went after you guys, cause really none of you made a habit of bothering me. I thought Allysia and Vallinane got along overly well, in spite of the tension between their ideologies, and I think that makes for interesting RP at least, even if it does provide some PK related frustrations. I know others were far more aggressive, but that's a playstyle thing. Some Nexus people are just softer than others I guess