Specificity and Training

You just need to do some bike tests. Use power or HR and find your threshold and pace off that. I didn't mind doing long bricks, but what your planning is unrealistic. I was doing oly distance bricks but it still did not help me in my 70.3. I had nothing to go on, and still cooked the bike.

You'll hear a variety of different views on this. I think some of the debate is not so much about whether these kinds of workouts are useful, as about what exactly they're useful for. Many are adamant that the physiological benefits, relative to individual workouts, are non-existent. Most agree that they can be useful for race practice and for learning about pacing, though they differ on how much of that is needed, balanced against the difficulty of these big workouts. My own view is that IF these fit into your plan, and if they will help you to gauge your progress and stay motivated, then they're probably a good thing.

You're proposing to build up to an over-distance bike ride, followed by an 8.75 mile run (in old money). I'm not sure that you need to go longer than the 90k on the bike leg, but if you can handle a run of that distance after a full-distance ride, then that should give you a much better idea of how things will be on race day, and it'll also be long enough to give you a better idea of the success of your nutrition plan. I'd suggest to aim for something close to race pace on the bike, and then to take things easier than race pace on the run. Folks who train with power typically recommend a HIM bike effort at around 80% of FTP (where FTP corresponds to the the power that you could sustain for an hour; and where the 80% is measured in watts rather than in MPH). 

I wouldn't be running 14k/9miles off of a ride. I don't think that will help that much.

Try to do fewer miles at race pace for your run.