1. I heard 0.4 will be supporting the steam version. Will it be supporting the 1.1 executable, or just putting the 1.0 executable in the folder and launching from it as a workaround?
The Steam EXE itself will be supported.
1.1. If it's supporting the actual 1.1 exe, will it still support the 1.0 exe? That sounds like double the work.
The 1.0 EXE will also continue to be supported; maxorator would be better able to explain how much work it was since was entirely his design.
2. Will it still be supporting mIRC? (Not encouraging it, really sounds like a huge holdback)
No, and I don't even think mIRC is supported now. No mIRC server was release for 0.3z R2; only Pawn saw an official release. 0.4 will not ship with any plugins for scripting in mIRC, and doing so would be highly inadvisable.
2. Who is developing VC-MP and what are their roles?
maxoratorVC:MP Lead Developer, has written by far the majority of 0.4.
StormeusVC:MP Developer (in training, somewhat); mostly performs small tasks and minor bugfixing; has also written the 0.4 Squirrel plugin to be used on final release
bakasanVC:MP Developer, has written many parts of 0.3; largely inactive nowadays
FalconVC:MP Developer, has written many parts of 0.3; largely inactive nowadays
VRocker, AdTec_224, Force, JuppiLU Developers, contribute to the codebase and help with various problems; wrote the base for the 0.4 server browser as well as the unofficial 0.3 Squirrel Server
3. Do you use any kind of, private, revision control for the project? Like SVN, git, etc.
Yes.
3.1 Are you accepting contributors?
No, VC:MP is not an open-source project. Developers are recruited as seen fit.
4. I know the release date for 0.4 is "when it's done.", but, by any chance, is it coming in 2014?
Most probably.