Let me number the questions for you and maybe we can get some replies...
#1.) I realize cushions come in several profiles, but are they rated for "speed" or "rebound" also?
Yes, some manufacturer's do take it to the extreme and test for speed and resilience. Olhausen's Accufast cushions have been tested to be the most resilient cushion over a longer time frame. I have yet to see a bad Accufast cushion. Maybe I can scan it and possibly email it to you?
#2.) I assume that if you were replacing rubber on a 7' table, you wouldn't want the rubber to be as lively as for a 9'?
That's a good point... There are cushions out there that will play really fast but they play well. So yes I would want the best cushions on a 7'. I'll check the list I can't remember off the top of my head but I know Brunswick Superspeed was the fastest but they also deteriorated quicker and lost resiliency, Artemis and then Accufast. Even Artemis will loose resiliency over time but they play so good its worth the money to replace them. Lively? Not necessarily, just accurate and consistent.
#3.) does the profile itself affect the speed of rebound, or doesn't it matter at all?
I think it does... K66 and K55 profiles have adapted themselves into quality pool tables for a reason. I have never found a consistent (American pool) cushion outside of K66 and K55, 35's and 23's are junk.
#4.) What brand of cushions do you recommend for a 9' table used for 14.1, with Simonis 760 cloth? A friend mentioned Artemis Tournament Cushions.
What type of table do you have? If you want something that plays well and you never have to replace get Accufast. If you are playing 14.1 I would recommend Artemis as well. I would recommend 860 over 760 just for durability purposes only, I like to play on 760 every once in a while.
#5) Back in the "Golden Age" of billiards, what was the model of Brunswick's top of the line 5'x10' tournament (commercial) table called?(circa 1930's)
There wasn't a specific top of the line table in those days that I'm aware of. You are talking of a Centennial or Anniversary perhaps? Circa 1945 Those tables were made to commemorate Brunswick's 100th year in the business. Great tables!