Re: Do I really need a capture card for editing hdv? Help!

My choices would be/are whatever the job demands. I already own a fairly robust multi-room facility, and have made many of the choices you're asking about.
No, I would not purchase all the gear you're talking about for the output/delivery you're talking about.
If you're buying a Mac and FCS because "That's what everyone says to buy," then I have real issues with that concept. We offer an Avid Adrenaline, Media Composer, Xpress HD, Sony Vegas, Adobe Premiere w/Matrox, and even an old Canopus Storm in our place. And we have FCS and Avid mostly because we have clients dumb enough to think that overall it matters on what we edit with. For about a year, we had one client (broadway producer) who thought we edited his stuff on an Avid because we put an Avid mousepad under the system and had a Newscutter manual above the monitor.
My own personal workflow, I prefer Vegas for most of what I do. Others will laugh, and that's fine by me. As you noted, my resume speaks for itself, so what hammer I use is my choice. I like the speed, the fact that nothing is converted, resampled, or resized when working in Vegas and that I can output a Blu-ray disc straight from the timeline from my EX-acquired footage. And have already provided footage to ESPN, EXPN, Discovery partner, Food Network, MTV, CMT straight from the Vegas timeline as both file-based HD delivery on a DVD-5, and HDD delivery of 1080p content to same client. But that's what works for me. It may not work for you.
Were I spending 10K on a system to edit EX footage that will find it's delivery on SD DVD and BD, I'd personally not choose another Mac, because I already own a couple, and personally don't use Apple unless the client demands it. Bear in mind, I walked away from Apple years ago due to poor ProTools support, and only recently came back to Mac due to pressure from a couple clients that made it worthwhile...but Vegas is still my preferred tool. When FCS directly supports the 1920 stream from the EX, I'll likely look at the workflow again, but the quality of image output between the two apps is the same, it's the workflow that's different. Only *you* can determine if that makes sense for you.
In a networked or multiroom/multi-editor environment, Vegas makes no sense at all, because while it plays very nicely over MXF and AAF with some apps, it doesn't play as nicely as it could.
For speed and ease of use, you can't begin to challenge Vegas with anything else. But if you need Motion (I somewhat do) then FCS is right back in the mix. If you're intent on converting the MXF to ProRes for some reason, then FCS is your answer again. If you're needing broad access for various post flows, Avid Media Composer or Adrenaline are your best options. Building a system today around a specific camera without a specific delivery project in mind is also a tad frivolous, but again...that's just my opinion. Maybe you've got a bucket of $$ that you want to spend, and it's not my place at all to tell you that you can't/shouldn't.
In other words, without actually sitting down and having a dialog, I don't think you can do this over the web. Some might, I don't.
All the opinions you get are what make this a colorful world, yeah? :-)

Douglas Spotted Eagle
VASST

Certified Sony Vegas Trainer
Aerial Camera/Instructor