Yes, you are right that aerobars are usually frowned on in pacelines; that whole getting skewered thing

There is one aerobar that I know of designed to be easily removed and remounted: http://www.redshiftsports.com/quick-release-aerobars/

You'll never be able to duplicate a tribike geometry on a road bike, but you can gain some of the advantages by adding the aerobars and maybe lowering the stack height; and you can move the seat forward some, but not as radically as on a tribike.

I have my dedicated tribike (Cervelo P2C) that I use for flatter races and training rides and my Trek Madone with aerobars that I use for hillier riding and racing. I don't do many group rides, but when I do it's on the Madone, with the aerobars.