1) How big of an issue are capacity and sightlines? Usually, pretty big. But considering the circumstances, a 14,500 seat layout may not be so bad. The MTS Centre (home of the Winnipeg Jets) seats just over 15,000, and I do not believe there were any complaints with the venue's seating capacity after the team's first season in the new location. Granted, that arena is hockey-centric, and every seat in the house has a good view of the rink. But the reality is the sacrifices may be worth it when we're talking about abandoning an arena that was considered outdated decades ago and is widely considered the worst building for any sports team. Yes, less fans have the opportunity to watch a hockey game without obstructed sightlines each game. But the seats with obstructed sightlines can still be sold at a discounted price, and the set of video screens facing that end of the bowl can have video covering the portion of the rink that is out of view. The fans can still see the Isles attack the opposite goal for two periods. And while the number of fans enjoying a full experience would be reduced, crowd volume would not be an issue. Like the MTS Centre, acoustics within the Brooklyn arena will be great, with a low ceiling and tight seating close to the action.
2) As fans grow impatient with the front office and anticipate the team's young talent reaching their potential, the move would be perfect for bringing life back to every aspect of the team. Brooklyn had been starving for a sports franchise since 1957. Thus far, the borough has welcomed the Nets with open arms. The hype has exceeded what any of us could have imagined, and the Brooklyn Nets have not even played a single game yet. A move to Brooklyn would be far enough from Nassau Coliseum to absorb more fans (people thought we were crazy for thinking the Nets would build their fanbase with this move), yet close enough to maintain the fans in Long Island. The public transportation setup is brilliant, as emphasized many times; one of the nation's best venues is now accessible for Long Island fans, New Jersey fans, and, of course, local residents.
3) This is the wrong time to depart New York. If I understand correctly, loads of young talent with heavy potential have been acquired in recent years. This is the time when fans are growing restless but will be ready to jump on the first sign that good times are starting. The Isles' fanbase is by no means weak. It just has little reason to sell out games at Nassau. A move to Brooklyn means a move to brighter lights (and a move to a more awesome rivalry with the Rangers).
The mindset I have had with the Nets' move is, "when you're this close to an amazing market, what reason is there not to move to it?" Once the Islanders are settled in the Barclays Center, I fail to see unhappiness with the capacity outdoing the satisfaction with everything else. The place will still be loud, and the limited seating would mean more demand for tickets. I think it's worth it. Oh, and "Brooklyn Islanders" sounds great!
For Nets' fans, as long as there is no tweaking that would take away from this place being basketball-centric, we should also be in support of the move. Not only does this add more than forty dates on the Barclays Center calendar for the Nets; it adds to the sports spirit in Brooklyn and truly heats up the Brooklyn-Manhattan rivalry.