Ok to start off, a little about myself. I am a journeyman carpenter with 15 years experience. I specialized in rough carpentry, mainly in residential construction. A couple months ago I had the opportunity to try my hand at timberframe and I loved it. As chance would have it my grandpa's old mobile home had a porch on it that was rotting from the ground up. My dad (who now owns it) and my brother (who now lives there) decided that I should take my new found skills and build a new timberframe porch.
As a carpenter I know or have access to all the local building codes to design and build a new structure using standard carpentry. But with timberframe I am need of some advice.

I am working with a few restrictions.
Keep costs to a min. (So no engineer/architect)
I will be using timbers we have sawn ourselves (woodmizer bandsaw mill) (spruce)
Keep the slope low ish (I'm thinking 5/12)
Display as much timber as posible.
Keep the room free of obstructions (no knee braces protruding into the room.

I am currently away from my computer and typing this on my phone. Once I get to my computer I will post a link to my sketchup design and post snow load info for the area.

The structure is to be 28'8" by 16" with the trusses spanning the 28'8". I have 3 trusses spaced 8' apart. We plan on using either 2x12 or 12"tgi joists 2' on center for the purlins. The roofing hasn't been decided yet but I'm guessing metal. I curently have the 2 end trusses designed as a simple kingpost with webs. The center truss they wanted more height to mount a light or fan from so I made it a scissor truss with an arch cUT inot thw bottoman chord. Both truss types have 8x10 top and bottom chord with 6x6 king post and webs.
I am using 10x10 posts and beams in the walls. 3 posts on each end under each truss. I plan on using standard framed walls to in fill between the posts.

Questions
1. Are my trusses good enough
2. Will the plywood on the infill be sufficient lateral wall bracing.
3. What is the r value of 8" and 10" of timber. (Wondering if I can display the timber inside and out, or if I need to inset and cover with some type of insulation).
4. Will drilling a 1" hole vertical through the center of the ridge and king post affect the structure of the scissor truss.
5 I'm sure as this design/discussion/build goes on I'll have many more questions.

Thx in advance for any help or advice offered. And sorry for any typos, ect as I am typing this on my phone.