Thanks for the reply. It seems there is no FTB server that allows griefing and twilight forrest. I guess everyone is scared.
There are surely servers that allow PvP, but "griefing" is almost universally considered worthless (the act of attempting to cause people grief is, in itself, destructive to a community). What you may want to look for would be "anarchy" servers, which are pretty much "no rules" in that regard. It's a play style that I'm sure takes some getting used to, but must be loads of fun, aye?
That aside, people are not really "scared", but more that they don't want to deal with other users destroying things that they worked hard to make. When you spend weeks building up your base, and some dillweed comes around and nukes it when you are offline, that just does not sit well with 99.934% (source: my randomized 99.9XX percent generator) of the people that play MineCraft.
So, find those of like mind, or if you cannot find a server that fits the bill, set one up. Good luck!