As far as I know chicken meets all of those requirements quite well. Chicken starts up extremely fast even for very large applications as long as you compile it.
The library ecosystem is obviously not as well developed as a major framework like rails or django but it is growing fast and covers most things you would need. A large benefit of it compiling to C and having great FFI support is that most libs don't have to be reimplemented in scheme but can just have a binding to an already mature lib.
edit: And if it doesn't have what you need the community is great at helping you get on the right track adding a new lib and gladly accepts well done patches.
The library ecosystem is obviously not as well developed as a major framework like rails or django but it is growing fast and covers most things you would need. A large benefit of it compiling to C and having great FFI support is that most libs don't have to be reimplemented in scheme but can just have a binding to an already mature lib.
edit: And if it doesn't have what you need the community is great at helping you get on the right track adding a new lib and gladly accepts well done patches.