To make sure the pack stays stable on a server i pay for and run a test server, not able to afford to run 2 servers so there shant be an official server from me (no point making the test server public as well thats the test server lol, we have had 3 map resets and countless bugs, we get them so you guys dont get them in the released pack

).
I will take a look at tubes / refined reLocation, Magical crops and the linked buildcraft addon (i make no promises as the pack is pretty full mod wise at mo and i dont want to hamper performance too much)
chisel 2 should not be an issue so long as it respects chisel 1 blocks (dont want to break players existing worlds) if it does not then it will go in the 1.8 pack that will most likely need a new world anyway(but judging by released mods and the new forge stuff is a long way away)
EDIT: i feel stupid lol, we are already on chisel 2
Aroma1997's mining diminsion caused some issues on the server (bad chunks and was dropped before the pack was even released) the inclusion of mystcraft means there is an alternative though i know its not as convient or easy to create a mystcraft world