With the new technic launcher, there has been a lot of new updates to tekkit lite, tekkit, hexxit, eg.
The first is that if you create a new world and it freezes at the building terrain, as it does with any computer with a not-so-good processor on it, you just quit everything technic related and reload the world. If you wait from anywhere to 2 secs-2 mins, it will come up. However if you wait, it will never come up. You have to restart it.
Second of all, all quarry bugs of worlds getting corrupted due to too many entities moving at the same time when loading a world, ie. Quarry, Cow, Spider in one chunk has been fixed. Now, as long as you have enough ram allocated to it(press the cog at the top right of the technic launcher).
Last but not least, They have reduced the mob spawn rate on easy w/ tekkit, tekkit lite and hexxit. This was because when you set the difficulty to easy, more mobs would spawn than if you had normal on. Watch out for those hidden mob spawners though. They spawn mobs after every 2 ticks. This has supposedly been implemented into the game, but I have yet to find one on any of them.
Thanks, Xeins