I have a really basic setup with two endoflames, open crate and hopper, with red wire and pressure plate, with a spreader going into a single regular mana pool. I've also got a solegnolia with redstone and a lever on it to stop my ring of magnetization from sucking up charcoal.

I've had a number of crashes while doing nothing/random stuff around my base.

http://hastebin.com/qelojesudi.vhdl

http://www.hastebin.com/ehovecozaj.vhdl

It looks like the mana pool and the solegnolia don't get along:
Description: Ticking block entity

java.lang.NullPointerException: Ticking block entity
at vazkii.botania.common.block.tile.mana.TilePool.recieveMana(TilePool.java:122)
at vazkii.botania.api.subtile.SubTileFunctional.onUpdate(SubTileFunctional.java:69)
at vazkii.botania.common.block.subtile.functional.SubTileSolegnolia.onUpdate(SubTileSolegnolia.java:34)
at vazkii.botania.common.block.tile.TileSpecialFlower.func_73660_a(TileSpecialFlower.java:99)

Vazkii gave up on porting to 1.8 a while ago. The port doesn't really count as a valid, usable version of Botania. The port is being done separately by someone else on williewillus/Botania

As @howtonotwin said, we are not currently the ones in charge of the Botania 1.8 port, any issues you have when using it should be reported to @williewillus on his repo, however I suggest you read the contributing guidelines first and make sure you replicate this with only Botania installed and that you are using the latest release.