"I would hate to have learned the hard way" It can be expensive. Famous last words is"but we used tar at the junction". You will need an old school framer that understand's his framing square. There's no need for much demo work before starting new frame. First decision is wherether whole house will be re-roofed,only front will be re-roofed of if shingles are in good enough condition to weave in for new addition. You and your roofer will make that decision,here's what you need to start framing. Peel shingles to deck where "starter plate"will lay. 1x6 or 2x6 plates are nailed in a vee on top of old decking where valley will be. If rafers are on 2' centers and deck is 1x boards or 3/8ths-5/8ths plywood,1x plates are sufficient and actually better for valley. Wider rafter spacing and/or composite deck require's 2x plate. Toe of new rafters will overhang plate and new deck will meet old deck a few inches outside of plate, therefore unsupported . Try and have edge of deck rest on old deck or be shimmed for support. There will be a nasty edge in the valley but it's simple to handle. Before tar papering,rip a wedge to soften the edge or use strips of shingle to build it up. Roofing is straightforth from there. There's options as what to do about cavity between underside of new roof and deck of old roof.

Thank you for the feedback! We definitely have plans to make the trim around the windows thicker and painted white. We know shutters aren't technically correct because they would be too small and obviously not functional, but there is just so much beige vinyl we wanted find a way to cover up as much as possible!

Here are some house styles I like... Ours is obviously smaller and we have less money than the people in these houses!

Well my current thought is to have the covered portion be along the front of the house and to have wide steps leading up the door and porch area...