As long as we have first-past-the-post, winner-take-all elections, it is one's rational self-interest to vote strategically against the party they least want to win, rather than for the party they most want to win.
You're being very myopic there. If you ever want B to become more like C, you must be willing to accept B losing in the short term. If B sees many of their votes going to C, then they'll move C-wards to pick up more votes. You have to think long term. Don't think in terms of C winning, think in terms of turning B into C, or at least something close enough to C that you're happy with them.
Side-note: I have never understood why the Republicans pander to the religious extremists - would those people ever vote Democrat? What do the Republicans have to lose by trying to pick up some moderates?
Those quantities are certainly mathematical dimensions. What is meant by 'hidden dimensions' is hidden spatial dimensions, i.e. directions, orthogonal to the perceived three. I've not kept up with the field, but last I recall these were theorized to be rolled up on very small scales. So something could move 'in the purple direction' by ±1e-9m at most - moving +2 being the same as moving -1 in a simplified version, as it's rolled up like a straw (iirc there are far more complicated shapes suggested for these dimensions).
One possibility of detecting these is if gravity isn't confined to the normal three dimensions, then at small scales it will not obey an inverse square law, but will 'bleed off' into the other small dimensions. Tests have been made to submillimeter scale, but that's far larger than I believe has been posited for the size of the extra dimensions.
In order to be qualified as a SolarCity supplier, manufacturers need to have effective Quality Assurance programs and refined manufacturing processes in place, and steady product and manufacturing quality must be demonstrated. Rigorous tests need to be passed on an ongoing basis, performed by a qualified 3rd party lab. Furthermore, we require that factory controls and in-line testing are in place to ensure quality is sustained over time and deviations are rapidly detected, so the deployment of faulty products in the field is prevented.
Whom computers would destroy, they must first drive mad.