I use a rasp for the majority of the middle level roughing and early tillering. I haven't had any trouble with it before, but you sure wouldn't want to use it too late in the process. The wood is very soft and a little bit of rasping goes a long way.
As far as heavy ELBs go, I haven't tried that kind of weight. I've only made hunting weight bows around 50 lbs with it. As far as the general design goes, they do very well. ERC is well suited to long bendy handle designs, though you might flatten the back a bit as it's a little tension weak. In the past I have backed them with rawhide. I don't have any at the moment, so I'm backing this one with linen. I know I know... Not supposed to be a good match. But this one is 74+" long, and only 50ish hopefully, so I hope it will handle it.
There is nothing special about the amount of heartwood on this one. The ratio you see is because I removed a large amount of sapwood. Probably an inch and a half or two inches of it. Ideally, you would of course chase a single ring after doing that. ERC rings tend to be about a half a pencil lead thick and all kinds of windy, so I just tried to get it as smooth as possible before backing.
The last one I made was in a similar manner though a bit shorter, at 66". There are assorted pictures of it with some deer and stuff the past couple years in the Shooting and Hunting thread. I hope this one turns out as well. We shall see.
