Alrighty. So first, >>349 and >>355 are not me (OP). Just sayin.
>>339
Satanists turn the idea of satan into what they want to believe, simple as that. So I highly doubt they just so happen to guess right.
>>349
There are three different kinds of merkaba as far as I know (but I'm no expert on that one): Positive, neutral and negative. I think it depends on how it rotates and what geometric image it forms in the result. I heard many times that some assholes "discovered" some sort of merkaba meditation and after people did it they were messed up in one way or another. Honestly, I think the whole merkaba thing is overrated. Not saying it doesn't matter, geometry is a big factor to everything. But people care waaay too much about their merkaba around their soul and waaay too little about their soul themself.
>>352
Well, yes. But if you create a tulpa and then absorb it you just absorb the exact amount of energy you invested. Unless, of course, your tulpa is somehow capable of absorbing energy from the outside - which should be possible at some point. For example you could teach your tulpa to, I dunno, hunt down lesser demons like those "I only stand around being scary" black shadow things everyone sees in sleep paralysis and then let it absorb those, then make it give that energy to you. Of course that means you'd have to learn how to do that stuff yourself first so you may as well do it yourself but in theory it should still be possible. Only problem with consuming a tulpa I see is that they probably won't like that - that combined with the fact that you want it to be strong so it can do that job is, uh, pretty problematic.
>>382
Humans gain energy through many different ways. Obviously they eat and drink. They also absorb it from the sun. Extroverts absorb it from others, introverts generate an extra amount themself but can easily lose it to extroverts. Energy can be shared through the morphogenic field of the aura (which, as most of you probably know, has many fields and this is just one of them) which is responsible for the energy exchange between people. In my opinion most importantly though, emotion can be turned into energy, too. And humans are pretty emotional. Oh and then there are "energy feedback loops" as I call them between romantic partners, male and female energy fusing sets free more energy then what has been put into the reaction.
Honestly the science behind energy is so complicated compared to how easy it is to use it.
Assuming by forceful evocation you mean basically forcing a spirit to be channeled into you. While you can force that process, you having control over that spirit when it is inside you is a whole different story. Of course evocation of a demonic lord doesn't exactly help your chances. Most people are totally not in control at all when they think they are when it comes to evocation of demons. It can be a usefull way to make a contract but you may as well do that non-forcefully and without letting the demon into your damn soul. I mean come on, that doesn't sound smart. You don't even know these guys. Besides the ranks of demons constantly change, they fight each other every now and then and often someone gets absorbed by the other. So it's very possible the demon you picked already is no more depending on how old your source of infomation is.
Personally, I don't "resonate" with the goetia too much. When you hear or read the name of someone you have met in a past life you get that weird feeling. Hard to describe. Often combined with that tingling all over your body that kinda feels like goosebums. But I don't really get that feeling for the vast majority of the names in the goetia. That and the illustrations look pretty ridiculous. I dunno man. To me this feels like a made up list.