These are things that more or less need to happen at some point in the future, tackled in order of interest (which may or may not be the order of usefulness). They are indiscriminately bug fixes or enhancements.
Some indirect calls or indirect jumps could be resolved at a later point in the optimization pipeline but right now the program flow doesn't allow going back to an earlier phase.
May be related to previous point. For now, a function with an indirect jump fails to decompile. (Indirect calls are handled mostly fine though.)
Fcd currently poorly handles global variables and merely outputs loads to some given address. This is a relatively low hanging fruit.
Fcd accepts headers to figure out function arguments, but not symbol files. There are no plans to have built-inDWARF/PDB parsers, but it would be a good idea to have an interface that lets users plug that information into the decompilation pipeline.