Thanks again solbes and JimRausch. I wanted to check back in and update you guys (better late than never, right?)
I ended up bottling without extra yeast. (The guy at my LHBS convinced me not too...). Initially, they did not carb well. Very light carbonation. BUT, then I realized the mistake I've been making all along, and that the "Tablespoon" I'd been using to measure out priming sugar was actually a tsp.
So, once learned how to measure, I reopened all the bottles, added additional priming solution, and recapped. 3 weeks later, they were all carbed quite nicely.
So a 10.5% RIS, w/ 3 months in secondary, dark and "suspect looking" yeast cake, then 2 weeks primed w/ too little sugar, then another 3 w/ appropriate levels of sugar... All resulted in fine carbonation.
Lesson learned - Yeast is resilient. Don't sweat it.
OH, another lesson learned with this brew session... Temperature of fermentation actually does matter. These fermented at close to 80 degrees cause I didn't believe that it mattered. It DEFINITELY affected the quality of this beer. The porter that I did from the second runnings was nearly un-drinkable due to all the high temp esters that were imparted. The RIS is still drinkable (especially after a few more months of age), but mainly b/c there is enough other flavors to somewhat mask the esters. Don't get me wrong, they are still there... A few that have tried it were completely put off by it and could not finish it. Others did not mind it at all. Me - I recognize the error, have taken steps to correct it going forward, and will happily drink the rest of the bottles while wondering how good it could have been.
Thanks again for the help!
Divine Brown Ale
How About Them Apples Cider
Mail Order Bride (RIS), Somewhat Overconfident Bastard (~ABA clone)