Words I dread hearing when I arrive home from work: "daddy, can you install a mod for me?" Usually the first half hour is getting rid of all the crapware they were tricked into installing as they tried to get the mod themselves.
Tekkit client, Curse client, and FTB client. If the mod isn't on one of those, they aren't getting it.
I use to do custom installs of mods and even a little bit of patching to make mods play nice together (namely recipe conflicts), but the time it takes just isn't worth it when you can grab a Direwolf20 or Tekkit pack and play right away. I do kinda wish Mo Creatures was still included in packs because my little sis loved the horse breeding to get endgame horses.
You forgot about the atlauncher. It has some interesting packs like TechNodeFirmacraft (a TerraFirmacraft based mod pack) that actually somewhat educate users about rising up from caveman to industrial era technology (real metallurgy names and semi-believable progression; at least until the end game where you make fantasy alloys to move blocks of non-finite water and lava about).
Ha ha ha! You nailed it. I dread the same thing. I tell him to stick with servers on planetminecraft, but even those are tied to specific versions of Minecraft. Then there's umpteen managers for mods and utilities to roll between different versions. I let his 20 something uncles deal with the mess; I have had it. I guess at 44 I have lost patience for such things.
While Minecraft is a neat concept, the whole thing really does need to be scrapped and re-written from the ground up.
Similar experience here, but I have a different take: I believe that the cesspool of malware, buggy code and incorrect documentation has been invaluable in allowing me to teach my kids about computer and network security from a very early age. They now know about sandboxing, testing suspicious code on a throwaway VM, port forwarding with client IP address filtering, and the perils of interface version skew.