There are very good parts and very bad parts about having the machines in your room. First off the bad parts ... they take up a huge amount of space. Until high level machines you can't make pristines and most likely by the time your guild hits lvl 25 you will be a lvl 50 crafter already.
On the good side, workshop writs and other tradeskill writs are shaped so you can finish those from your room. Also, unless it is the first item in a combine then the level of the finished item does not matter. And most importantly for botters ... it does not look suspicious if you are standing infront of your tradeskill machine for hours on end doing nothing because you ran out of items to craft.
And yes, crafting and tradeskilling at the same time in your room DOES work. I think that is the best reason of all to do it.