When I was there a few weeks ago, DLR hotel guests could enter through the GCH entrance at 9:15. In the past (during peak times) it has been at 9:00. The main gates open at 9:30. Sometimes Soarin' and Little Mermaid will open around 9:20-9:30 - when this happens, there is time to get a WOC FP, ride Soarin', get a Soarin' FP, and ride Little Mermaid before rope drop at 10:00. Yes, there will be a lot of people at rope drop. Without construction walls, there were two rope drops - one in Sunshine Plaza and one near Little Mermaid. Since construction there has been just the one (at least when I have been there) near Little Mermaid, but who knows what it will be like in April.
About TSMM - I used to be one of those people lining up for rope drop to be the first on TSMM, but have since decided it doesn't make sense. If you are right at the rope, and are super fast (read: have no children and break the "don't run" rule), and there isn't another rope drop somewhere else, you will get on with little wait. BUT - if you have been waiting at the front of the rope drop line, you've already spent 30-40 minutes in line.

In the morning, the line for TSMM quickly builds to 45 minutes, because everyone else wants to ride it first thing in the morning too. If you are not first in line and you are not fast, then you will wind up waiting just as long, if not longer (taking into account the time you waited in line for rope drop) than you would if you went to ride TSMM at some other time that day.
Just my .02.
