FYI regarding crashes: whether I'm using LNP, vanilla, or Genesis, if I gen two worlds in the same session of DF I just about always get a crash since using 0.34. Likewise if my DF.exe RAM usage gets to 2GB while running a fort, crash.
The first looks like leaky memory, or something from a previous gen not getting properly purged for the second pass. My workaround is to gen a world and see if I like it. If I don't, I exit DF, delete the save folder if needed, relaunch DF, and gen a new world. No crashing.
The second is due to memory address limitations in 32-bit applications. It's largely due to embark size, but also is affected by all the stuff that kills FPS. I find I can safely run a 6x6 embark until I'm bored. Larger is iffy.
You can check by running your task manager or whatever and see how much memory the DF process uses when you embark. (ctrl-shift-esc for Windows brings it up without dealing with ctrl-alt-del and clicking around). I find if my memory usage for Dwarf Fortress.exe exceeds about 1.5GB at embark with all my usual enhancements going, I'll hit long-term crashes. Either many years in, or sooner if I have hundreds of dwarves and thousands of stones and gobbo chunks and such. YMMV on that.
Neither is strictly a LNP issue, but it can contribute. Graphics eat more memory. DFhack utilities are part of the 2GB DF.exe max, so running workflows and Soundsense and all that jazz also contributes.