Questions Re: Time & Phase Alignment

Some basic questions here. Hope nobody minds. Some of this stuff I don't quite understand. Have recently become very interested in T&PA after hearing both the Green Mountain C3 and Thiel 3.7 at RMAF, both of which tout this design quality and both of which were among the best speakers I've ever heard, anywhere.

Questions:

1) Basic definitions. Time-alignment means that sounds that start at two different drivers at the same instant will reach your ears at the same instant.

Phase-alignment means that there are no phase errors between drivers: the same frequency waveform, for example, produced by two drivers (in their overlap region) will be entirely in phase with each other (and thus completely reinforcing).

Are these definitions correct, correct but lacking, incorrect, or what? I find there is a lot of either misinformation or misunderstanding in the industry about these things.

2) How does a sloping baffle produce time-alignment? I really don't understand this - I would think that having the voicecoils of all drivers in the same plane would, in fact, produce time-alignment. Is the slope to compensate somehow for the crossover?

3) On that note, I don't understand why it is that 1st-order crossovers are phase-aligned. Perhaps this is stricly due to the implmentatation - a single cap produces no phase delay? But I don't think that's the case... so why is it that 1st-order xovers are said to be p-aligned and higher-order xovers are not...? Or is that, perhaps, myth?

3) Thoughts on the superiority of coincident midrange driver/tweeter vs. completely separate drivers? I certainly see the benefits of the former but it must introduce some problems as well - there must be distortions caused by the entire tweeter assy moving with the mid driver.

Thanks much in advance to someone who can shed some more light on these topics.