1. Very very very likely, based on what we see in Shanghai and other themeparks across Europe.
2. No idea, could be.
3. No date mentioned yet. But you can find rumours for why Disneyland would open in a particular month.
As I mentioned to Tedwash, several themeparks in Europe have adopted a reservation system. Some have 2, one for AP holders, one for regular guests. AP guests got in those cases priority over other guests, but the amount of AP guests to the park is capped.
I'm not sure if Disney hotel guests will get priority over AP guests or not. Of course hotel guests bring in more money, but as DL is so dependent on their locals, many who have an AP. Disney will need something good in place to please these AP-guests. Also, because the Disney owned hotels are very overpriced, in comparison to the hotels surrounding Disneyland, it could cause a backlash as it will make visiting Disneyland something for the rich.
Also, if Disneyhotel guests would get priority, what would that do for the relationship Disneyland has with the surrounding hotels on the boulevard? Also this can cause backlash from their partners.
I only see Disneyland give priority to Disney hotel guests over AP holders if they also cap the amount of guests in the Disney hotels .