Ideas for overhauling the Minecarts (and railways)

Minecarts right now are, outside of Redstone, kind of boring. They don't look that good, and aren't even the best mode of early-game transport due to horses. The only uses I can think of are making rollercoasters and Redstone contraptions (of which I am very bad at), so I would like it if minecarts were generally more useful for transportation.

My Ideas

• Add a minecart that can carry two entities at once. Along with this, maybe a double-chest Minecart as well. Perhaps the larger minecart could have some sort of brake, too. 
• Ability to link minecarts together, making Furnace carts not unruly and useful.
• To more entice people to make railways, perhaps make rails cheaper. (maybe two sticks, one iron bar [not ingots] each.)
• Increase potency of Furnace Minecarts (maybe faster than the max horse speed?)
• Maybe more rail types? Something to make junctions & changing direction a bit easier.
• Improve the minecart models (some animated wheels, perhaps.)
• Maybe Lanterns/Torches on minecarts? This would require dynamic lighting, though.

I don't exactly want to replace the minecarts we already have, as that would totally break many sorting systems and other Redstone builds, but add upon the mechanic and make them more enticing to casual players such as myself. Like I said, these are just ideas I've been thinking about, so take them with a grain of salt, and please discuss ways to improve the ideas! I'd love to hear them.

Hope this is in the right category.