Early - you should have no problems using buses.
if you get there a bit later, plan to stand on the far right. They open additional bag check lines there (using temp tables). We were behind about 25-30 people when we arrived. Stood on the far right and shortly afterwards, additional bag check lines opened and we scooted over and were second in line for bag check. From there, we made it to 3rd in line for the tapstiles.
If you make it through bag check line fine but there is a long line for tapstiles, choose the line on the far left. They will eventually open the pre park open breakfast tapstiles to the general public and if you are paying attention, you can scoot over.
RD is very doable but helps to be strategic and be able to walk fast afterwards too. Alternative is entering the line at park closing. My DD entered at 9:26pm (for a 9:30pm close). The sign said 90 mins. She waited 45 mins.