No endcaps these are the cheaper one piece slash down.

 

I had the SE off road slip ons and they were to loud for me. Got a pair of SE 65115-98B , same as Supertrapp SE. They are great. No more ear burn !!

 

I've been thinking the same thing as you lately.
Great performance , fuel mileage , but just a little loud after a while.
To answer your questions.
1 , maybe
2 , probably
3 , probably
But , you know what you have , how it runs , and the combination that works.
Give it a try , if it goes rich , lean it back slightly.
The CV carb is a really neat design , in that it will compensate for fuel delivery as air delivery goes up or down.
The stock mufflers will restrict flow somewhat , which may flatten the power a little , but not change the jetting that much.
I did quite a bit of tinkering with my carb with only the big sucker as the first mod.(no mufflers)
I richened it up and gained both power and fuel mileage.
My best mileage was with fullsac duals , but didn't like the throttle response from 1600-3000 rpms.
With the stock pipes and V&H classics , I got back the low rpm response and lost a bit over 3000 rpms.
For my riding style , I'm happy as a clam.
Last mileage was 44 mpg 2 up on a fairly long ride.
It won't take much to change the mufflers , so give it a try and let us know how it goes.
I'm sure others are curious.
Mick

 

Thats what my wife uses, and they only cost $ .67 cents.

 

We use our $650 Digitial ESP SHooting Ear plugs when we ride anything longer than 50 miles.

Would e cheaper to have bought quiet pipes

Good Luck

 

I dont blame you for going back to stock.. I have a 08SG with almost 4k on it (I'm a harley rider not a owner) and the stock pipes open up and get louder i can honestly say... after riding the shh..t out of mine ... but the motor is starting to ping so i gotta get something soon..