Okay - After reading what you wrote - a few times - and referring to the URL etc... I think I have some general suggestions.
1) The only reason to bridge is if you need more power for a specific speaker. ie: one room is larger and has bigger speakers or you are using 4 in series or parallel.
2) I'm sorry about the homerun wiring issue. Welcome to the joys of whole house AV. You always want home runs - the more the better. It allows you more control today and in the future if you make changes without having to tear up the house and paint again. Also - there's the practical aspect related to power loss over distance / impedance issues...
3) Consider your run lengths and use the proper gauge wire to minimize those effects.
4) Know your local code on low voltage wiring. Color coded CL-3 is best. There are many brands that aren't too pricey that are generic... Just make sure it's stranded copper... (shielding is not typically an issue with speaker line - just don't run parallel with high voltage power runs within walls etc.)
I hope this helps with your project. Slow and easy wins the race. Take your time, think it out (as you are) and you'll end up with a system that addresses your needs both today and into the future.