ok here's the deal on three.

There are sewers to the south, east and west.
the ones to the south get you in the upper level to begin with,
the one to the west has the ladder, and the one to the east allows you access to the boss, by letting you get a key.

there is a way to get down in the middle sewer area that you cross over the bridges above, check the statues on the east side pretty closely :O)

the eastern sewers you fall into if you aren't careful :O)

once you have been in all the sewers and done what you have to do, you can use the ladder in the room next to the enterance so you won't have to travel all the way around through the sewers and the block puzzle any more. :O)


Now I am in desperate need of the raft
yep, it's time, you need it in level 4.
remember the guy said you would need a rope or something?
or maybe a hookshot? :O)

I think you have the wrong red tree too, if you're talking about the red tunic you see, there's one on the southroad in Northern Hyrule.