Hope these can give you some direction, let me know if you have any follow up on any.
Why - They are very profitable, one of the most profitable games around today (for the winners of course). Casual players love playing them becuase they are fast paced and anybody can win. A lot of players are fooled by this, because they correctly see that there is a very low edge per game for the better player. However, the games play so fast that this small edge adds up so fast that hypers are much more profitable than turbo or regular speed HUSNGs.
Rematch - There is a button on sites like PokerStars that allows players to accept or decline a rematch. Merge has one of these as well and a few other sites do too.
Best players - Serkules, Skaiwalkurrr, Adonis112 are probably considered 3 of the very best. There are many great players, check out our High Stakes Rail forum here for some other names of high stakes hyper turbo winners (and the weekly Sunday reports).
Sifosis - Very good hyper player, consistent winner and grinder.
Stalling - PokerStars will warn players if they do this and are reported. It usually ends there and they have indicated if it goes further they will take action, but I'm not aware of it ever going further. The rule breaking on this one is "against the spirit of the game/abusing the time given to you to act." So I would suggest not stalling, plus it'll just make a better player want to play you even more (just like talking trash, it's a sign of weakness from most people). Put another way, one of the most illogical and frankly stupid poker regulars there is is probably the only public advocate for stalling on 2p2. He thinks he has an edge at 0-8bb against regulars, so he stalls until that area. His opinions on many other issues are what makes me call him stupid though.
Duration - Used to be closer to 2.5 minutes on FTP, but it seems 3-3.5 minutes for many nowadays.
6 max - These are viable, probably the best regular SNG hypers to play for profitability from what I hear. But one look at the sharkscope leaderboard (or just sharkscope the top players in each game and include rakeback too to be fair) gives you a clear answer to this one.
Hourly - These can get into the several hundred dollar range.
SNE - I would imagine $100s or $200s for a heavy grinder. Most SNE HUSNG guys at least play $300+ for extended periods though I beleive.
Downswings - Since your edge can disappear with bad play or leaks so easily, game selection etc. it's really tough to say. Even some of the top players have had long poor streaks. Purely on variance alone? Depends on your winrate, but be prepared to handle the rare 50-100 buyin downer. However, many downswings are caused by poor game selection and poor play. Just know that negative variance (chances of a big downswing for example) are attached to winrate. The higher your winrate the lower chance you'll downswing. Mersenneary has an excellent article on this, go to free > articles and he has some charts on what a true xx% winner should see in terms of downswings and frequency (variance isn't nearly as bad as ppl think is the short answer, it's often bad play or bad game selection that causes a lot of it). You do see some nasty EV graphs though. Coffeeyay just posted one in the 2nd newest post on the main page (Coffeebreak 2).
Volume - Should be good. Fish depends on you. If you don't have good stats, you tilt, stall opponents, talk shit to opponents and/or don't play well against regs, you'll get sat a ton by regs. If you have good stats and play well and stay in line against other regs, you'll end up sitting first and not facing too many regs, mostly fish. Lobbies can get crowded at times with regs, but it's often a "take turns" sort of thing.
Sharkscope - It's good to know what to expect, but don't read too much into it. Just gives you a decent idea of your opponent's skill level. Don't overlook average buyin, it's important, and don't assume a guy is horrible bc he's down money. He could just move up and tilt, or he could have a few horrible leaks that you need to find and exploit. People use sharkscope wrong all the time and just assume "bad stats, easy fish" and "good stats, really good." It's not nearly the case.
Ability - Since Sharkscope has been restricted by Stars on displaying ROI and profit information, they have tried to develop an overall rating for players that includes their buyin, profit, profit per game and more into one stats; ability.
Why HUSNG - Our free content is better than any other site's paid HUSNG content. We have several tiers available from there, from $50 to $220 right now, and we'll likely have more at the lower and higher end of that range available within a few months. We have a great track record since early 2009 when we launched.
Routine - Most experienced regulars have a sort of "default" game they play starting on hand 1. They build this default game based on experience (and often database stats) they've built up from thousands of games against the field. Now, they don't just play this for 10 or 20 hands, they slowly work their way out of this default game based on observable information about their opponent. This starts from the very first hand (a fold, raise or jam for example) and continues on each and every hand. Of course, information on hand 1 means a lot less than information from 3 hands (on average), Bayes Theorem and so on.
Coaches - Coffeeyay, Cog Dissonance, Bernardc and HokieGreg are good hyper options right now. Prices range from around $100 to $250 per hour I believe. I'd suggest watching their videos first, there are some free ones as well as a variety of paid options, to give you an idea of who is the best fit for you.
PT4 vs HM 2 - Right now most prefer PT 4. Some notecaddy huds are being developed for HEM 2, specifically for HUSNGs that might make HEM 2 a more competitive option. Until then, PT 4 is the clear answer.
 

Wow, as always a thoughtful and detailed post! that is why everyone loves husng.com.
 
Thanks again Rypac for a great site.