1) http://elderscrollsonline.com/en-uk/preorder. Toward the bottom, pre-order bonuses. The play any race with any faction is not related to the Imperial edition it's pre-orders. Anyone who pre-orders will get that bonus.
2) For those at launch it will be like most other games. A large number will have the CE bonuses, they will not be a rarity (especially as all bonuses in game are avilable through a digital version which is effectively unlimited in supply. Over time they will become more so as people quit (unless this gets released in another form down the line).
3) The concern isn't primarily about having those outside the factions original race. The issues people express is with the story line and content being developed without that being a possiblity and 2 months to go being altered (with concern as to how this will be adjusted when it comes to the writing). Also with the pre-order bonus it opens the possibility that you may have, for example. High Elves being the most common race in the Daggerfall Covenant.
4) People keep saying racial traits provide a minor role. I could say the moon is made of cheese. Neither are accurate. The racial lines may not be THE skill lines to get for every build but they are no worse than many other skills available. Those who do not spend money will not have access to those of the Imperial race (and there may be no advantage, but on the flip side there may equally be an advantage) and any builds they may benefit.
5) Prior CE in game bonuses are usually cosmetic or short term advantages, this offers a race with distinct differences to other races permenantly which may or may not (as mentioned in 4) have gameplay impact.
6) There is no evidence that they will not either. They said there would be no pay gated content or features, that everything would be avilable for the box and sub. That is now looking less than truthful, so good faith has been damaged for many. Trusting that though they have misled their fanbase once they won't again is akin to being the frog letting the scorpion climb on board to cross the river. Also imagine the uproar from those who did purchase what they believed to be exclusive content (because it is worded to imply such) when it is made available to all.