I can address several of the last issues. You are NOT allowed to begin your trip without a properly mounted and operational ELD unit, and should it fail enroute it must be repaired or replaced at your DESTINATION. That is where the 8 days come in, while some otr drivers have cross country trips where it is 5-8 days to destination, our dispatches are generally less than a day. PHL-HRS, CLT-GAF, you name it, it is a destination, according to the law it must be repaired or replaced, no gray area. There are very few exceptions, the Companies failure to install and maintain ELD's is NOT a valid reason.
The dispatching of non-ELD vehicles comes down to US. If you or I hesitate to operate a non-compliant vehicle, fine you are well within your rights. As we all know there is always someone who, for whatever reason will say, "If that a$$hole won't do it I will, I don't care, I've got to go". Usually the same ones who never pre-trip, hook-up in 8 minutes out the gate, every terminal has one. How many times I have heard, "so and so doesn't have a problem with it", all I can say is do what you have to do, but verify and get a witness.
Do I like the ELD? Yes and no, in our type of work they simplify the process, not only by keeping track of hours, but saving time with arrivals, departures, and updates to hooks and routes. Do I miss skipping lunch from time to time, yes, when you hit your 8 on an exit ramp I miss the paper.
Search 49CFR, part 395, subpart b. Its all there
Stay safe