No, that's fine. What's bad is how much RAM it then eats when a player logs on.
In Minecraft, the world is split into chunks. Chunks are only loaded (rendered and calculating on ticks) when a player is within a large area (Depends on the rendering distance). This doesn't matter for too much other than furnaces or mob farms in vanilla Minecraft.
In FTB chunkloading is much more important. This allows you to keep machines running even when you aren't near them, or aren't even online. (See: Lava pumps)
Yes, you can live without chunkloaders. However it makes FTB much harder for almost all the packs.
ChickenChunks (The main chunkloading mod) is able to restrict what happens chunkloading wise. You can only give normal players 10 chunks or something. And ChickenChunks will restrict BuildCraft (Quarries autochunkload), RailCraft (Anchors and Anchor Carts), Steve's Carts (Chunkloader module), Misc Peripherials (Chunkloader+modem turtle module), and ChickenChunks (Chunk loaders and spot loaders).