Apologies for late reply, playing catch up. Only thing I see in the build are the 255 cams. I do not know if people have ran the numbers on these or if they are choosing them because they are new. With the correct pistons to use with those heads you'll be at 10.5 compression (not listed on your reply, but I assume that is what will be used). It is VERY likely to have severe detonation, heat and starting problems (even with compression releases). Cylinder pressures will be way too high causing difficult, if not impossible, tuning issues. Better choice would be the 258's or similar. the 251's or 257 could be other choices, but tuning will be critical and starting may still be an issue.
To your questions;
1. Do not polish the intake ports. This will cause fuel seperation and reduce power, the CNC finish is nearly perfect. You can polish the exh. port and combustion chamber to minimize carbon build-up, but this is only temporary, over time build-up will occur. Better to have the chamber, exh port and exh valve ceramic coated to keep heat in the port and pipe and out of the head casting, guide and valve stem.
2. The T-man 590 or 650 cams will work. Other choices would be the TW9f, S&S 585 or 625 and Andrews 67. All available in gear drive. This is a big motor with big ports and will take deep breaths, so it can stand (and want) more duration and timing vs. smaller motors.
3. The Mikuni 48 would be my choice but the 51 CV is more user friendly. Because of the smooth bore design, Mikuni's flow more air size for size vs. a butterfly carb and so can be smaller. Zippers, Rivera and T-man all have excellent Mikuni kits. The 48 is the largest Mikuni currently available and some shops are modifying them to flow more air for larger motors.
4. The quick installs will be fine and allow for more cam choice options (base circle differences will not matter).
5. Check out our dyno library exhaust files on this site for examples of how many types of exhaust have worked o builds or tunes we've done. The VH Pro will have a torque dip around 2.7k but not as bad with the larger motor size of the 113 vs. a 95. The VH Ovals on your stock head pipe will produce the best power from 2-4k but will fall off above that, more so with a bigger motor. We do a "y" pipe mod to the stock head pipes that helps with large motors. Another good choice may be the DD Fatcat 2-1 but it'll be a bit louder than the VH's. Your exh choice will be the single biggest influence on the shape of the torque curve (more than the cam choice).
6. Yes, you'll need to upgrade your clutch. We like the AIM/TPP lockup. You can get more info on this on their web site www.aim-tamachi.com
7. You will not hit your projected numbers with the 255's. With a freeflowing exh (bad for 2-3 area) and more appropriate cams these numbers are very realistic (based on 5th gear runs corrected to STD). An exh that helps the 2-4k area may dip down to 115 hp peak but you may also see 120-125 torque.
8. This should be a very reliable build. More so with an exh that focus' on the 2-4k area because the motor will not have to rev'd as much to make power for passing, hills or just plain accelerating.