Yes, it is, but it is nothing to mess around with. It can lead to great harm for you. It is also not fair to take from others, when the Source gives so very freely.
not fair??? it's the way of life... you survive by taking of others, animals hunt other animals to survive, other animals (herbivores) eat plants, etc, you survive by taking what you need. We psychic vamps have loads of spiritual energy, at least, I have, but I still need to feed from time to time... we become weaker when we don't feed, I haven't fed in months and I'm very weak atm (physically) though feeding drains physical energy from time to time (I haven't really had problems with this) it's like being drained after a good run, whereas we don't feed, we are just drained and can't get the physical energy we need.
Nyxus: When we feed on energy of others, we do get more physical energy, just rest after feeding and you'll feel that you'll have more physical energy.
As for forcing it, it's not harmfull at all, just practice enough before applying it.
A great way to do this is to meditate, chakra is a form of spiritual energy that can transform in physical energy when meditating, the bottom 3 (the first 3 you need to open when meditating) will give you a boost in physical energy whereas the top ones (crown and 3rd eye) give you a boost of spiritual awareness, the others are a mix of both and just feel relieving (which is a good thing).
If you train enough on meditating, you'll be able to open the chakra's without using meditation, I had this, but I got stuck with a parasite and since I destroyed that thing I can't control my chakras en other energies anymore, I took a lot of damage getting rid of that thing.
If you feed though, try to feed of emitted energies instead of draining people, it's not as refreshing, but that way you won't harm anyone and you'll be less drained too.
