Well, the two solutions that you have declined are likely the best ones available.
With RPGMaker VX Ace, you get a pre-built bunch of tools, some which are more for the "generic" projects, and others which can actually help you well. You can generally take or leave many parts of it. For example, it comes with a bunch of assets,and it has a sort of character generator, but you can easily just use your own assets instead, and probably should. The really usable parts though, are the database and the game engine. The database system is great because you don't have to create your own code for RPG stats, items, weapons, etc... And the engine is great because it contains the whole movement, map, fight system, tile engine, etc... All of that can save you lots of time. It is true that there are limits, but many of them can be overcome by scripting your own. The original battle system for example is a front view battle, but you can easily find several different battle engines that have been scripted, for example a side view system, and even some "real-time" systems that have been done as well. Ruby scripting is the base of the engine, so you can modify much more than what you see in a quick overview look at the engine. This is my first/best suggestion because it is tailor made for RPGs and you can do a lot with it.
I'd also recommend GameMaker. It isn't meant for RPGs directly, and so doesn't have RPG Stuff that RPGMaker does, but it is more able to be customized to your game. It also means that it will take more work and you will have to script your battle engine instead of modifying someone else's, except in the case that you find an example which suits your needs. It has some included things though that help with RPGs, like a basic tile engine, and the IDE does the loading of assets for you once you import them too. It is built for more general 2d game creation, so though it does many things for you, it provides a scripting language with which you can do almost anything with 2d, which easily includes anything an RPG would need. It also has advantages over RPGMaker. It allows you to do more, for example other game genres, so learning it will have advantages in the future, while RPGMaker isn't very good for anything but RPGs, GameMaker can do anything 2d, and actually has some 3d capabilities too. The last thing I'll say about GameMaker is that GameMaker Studio is getting better and better. It has a price tag on it, but you can get exports for mobile devices, HTML5, and windows/mac/Linux as well. It is also getting more and more features, and recently got access to shaders, which work with 2d and 3d, and can do any graphic effect that your shader writing capacity can do.
Well, it is up to you how you go about this. But in general it is recommended to use the right tool for the job. So instead of coding your own, you are better off using something like RPGMaker, assuming it can do what you want. I'd assume that it can once you figure out the Ruby scripting system. And where RPGMaker doesn't work, GameMaker would do the job. There isn't much reason to code your own engine when either of these two would do it for you with much less work on your part, getting your game done faster.
