2Young, thanks for the comments on the Clif Shot Blocks ...I may try some of those.
liquors, welcome back!
Concerning your training questions: Don't overtrain. Trying to pack in extra workouts will probably have a neutral, or possibly negative, effect. I'd even suggest focusing on three bricks built on longer rides/runs than the four you mentioned. I think you'll deceive yourself into thinking it's not so bad to bike 25-30 miles and then run several miles (!). Better to get a sense of what it's like to get off the bike after 3 hours and then running some miles. In general, I'd suggest focusing on long swims and long bike rides - if you come out of either leg tired, it makes the rest difficult, so build as much endurance as you can for those two disciplines. The run's going to have to take care of itself. I just don't think you can adequately train to run a half-marathon after four hours of swimming and biking. You have to control those first two legs, take in calories and fluids, and be mentally ready for the challenge of the run. And that's my last suggestion - work on your mental planning/imaging for the run. Know what you'll do and what you'll focus on if the run gets hard and your mind tries to turn negative on you! The 1/2-IM pushes your boundaries and takes you to your physical and mental limits.
I ran 8 miles on Wednesday morning at a bit under 8 minutes/mile - my first good run since my race a couple weeks ago. It felt good to get out and push it. But then on Wednesday night, walking across a room at home, I managed to stub my toes on the edge of a couch ...the middle toe took the direct hit with a solid "crack." It hurt like a son-of-a-gun, so I quickly iced it. Now it's got some ugly colors just below the toe nail. I do believe I might have fractured somethin' in there.

It's still a bit sore, but I'm walking OK. Nothing looks or feels to be out of place. I'll be cautious over the next week and see how it's doing.