@epidemia78 So sorry I didn't respond last night when the post popped up in my notifications. I've seen the retrogen issue before, it IS rather distinctive
It's one of the major reasons I don't make long-term worlds without Reika's mods in the pack if I expect I'm going to want them in. I also wait for major versions before doing so, simply so that I'm less likely to have a worldgen change, especially in CrC; not that I'm saying there WILL be changes to worldgen in ANY of the mods, but if there are, they'd come in a major version release, so I plan for it. I'm not kidding when I say "long term", I expect to play long-term worlds for half a year or more.
Liteloader is a lot like FML, except lighter. They co-exist just fine, and a lot of mods that only affect the client can be made in LiteLoader.