What time of year are you going? Two days can be done in the "off-season", but if you're going during holidays, spring break, or summer, I recommend 3 days minimum to see everything, but 4 days if you like to take it easy and go at a leisurely pace. Even though WDW is larger, DLR offers more attractions in less space.
Hoppers depend on your touring style. If you're only doing 2 days, I don't think the hopper really helps. One day in each park is fine. If you do more days, get the hopper. It's nice to be able to go to both parks on your last day to finish up loose ends.
Get maxpass. It's worth it. I wouldn't have said that at first, but after using it once, I love it. Unlimited photo downloads and wireless FP booking.
ADRs start 60 days out I believe. I could be wrong. We don't usually do ADR. There are quite a few QS restaurants and often the wait at TS restaurants feels like a waste of time when there's so much to do.
What hotel are you staying at? If you get EMH or MM, use it. It's worth it. No matter what, get there 30 minutes before rope drop in the morning. It's nice to be able to get into the parks and get stuff done before the crowds get bad. If you don't have MM or EMH, start at the park that doesn't have it that morning. It evens the playing field in terms of competing with crowds.
Overall, DLR does not require as much planning as WDW. Make a list of attractions you want to experience. Try to organize your time by area to avoid running back and forth. And make use of FP for RSR, GotG, Soarin', Star Tours, Indy, and any of the mountains. Have a great time!