For now, I'd forget about using phantom power. You've got a lot of learning, experimentation, and development to do before you can start thinking about the power supply...
My best shot so far is my brother who taught himself Python last year, so he was planning on giving it a go using some translator? Programming Arduino with Python? He and I both have a sound engineering background.
That's good. Once you know one programming language, it's a lot easier to lean another one. The important concepts (mainly loops & conditional execution) are the same. And when programming a microcontroller, you're using special functions & libraries specific to the particular hardware, so you're not using much Standard C/C++ (or Python) anyway.
There is a FREE online DSP book called [u]The Scientist and Engineer's Guide to Digital Signal Processing[/u], By Steven W. Smith. The book isn't specific to any particular hardware or language. I believe the examples are pseudocode. So you could "play around" with Python or C++ on the computer before getting any particular hardware.
I'm not saying you can't do it, but DSP is generally considered "advanced programming" and if you were taking Computer Science in college, you probably wouldn't take DSP until your 3rd or 4th year. (And by that time you'd also have lots of math under your belt.)
On the hardware side, I'm not sure if the Raspberry Pi can handle it or not. You'll probably want to run it without the operating system. The BIG PROBLEM with "regular computers" is the multitasking operating system, which is always multitasking even when you're running one application. That means you need buffers, and buffers are delays. There are "tricks" to minimizing latency and obviously some people are using PCs & Mac's for real-time audio but getting the latency down can be a pain and it usually takes a powerful computer. (The faster the computer can finish the other tasks, the faster it can get back to reading/writing/processing audio, so you can use a smaller buffer.)
I don't know if you need one, but there are specialized DSP chips and you can get a development board so you can start testing & writing software before building the hardware. (I don't know what the DSP chips cost but last time I looked into this, the development boards were several hundred dollars... Apparently not meant for hobbyists.)