I can answer your questions. You only need a blow off valve with a blow-thru system because when the throttle blades shut, the pressure pulse bouncing back to the turbo impeller could damage the turbo. With a suck-thru, you don't encounter that. So suck-thru systems are cheaper and easier to build.
The disadvantage to a suck-thru carbureted turbo is that your throttle blades will end up icing up. Even in the summer, that can cause problems. I had a friend do that on his pick up truck, and that was his main worry.
You can intercool a suck-thru system if it's fuel injected. That's how my Shelby Charger was intercooled and it worked well. You can also intercool a carbureted suck-thru system the same way that roots superchargers can be made intercooled. Although it's kind of rare. I've seen freon and water-cooled intercoolers right inside the intake manifold on the pressure side of the roots blower. And it seems to work. The fuel will stay in suspension if it has a short enough path. How you'll do that on a suck-thru turbo system will take some ingenuity on your part.
There is one other way to intercool, and that's if you have the suck-thru charge pass through a finned pipe sitting in the air-stream. I see no reason why that wouldn't work, since there are no internal obstacles for the fuel to condense on or fall out of suspension. Look at the old Mopar motors with the really long intake tracts and carbs out past the valve covers. The fuel stayed in suspension on those engines and they made really good torque.
