some questions about Xbox 360 hacks

Well, I couldn't understand much from overcomplex wikis, and I hate how subreddits remove over asked questions telling you to read the overcomplex wikis. The hacking wikis displayed an overwhelming load of information on me, and I only wanted to make sure I understood correctly. So, I have many questions to ask, and I'll be thankful of any explanations: Is there any way other than JTAG to get copied and downloaded ISOs working on the Xbox? how will a DVD drive hack work and does it worth doing or just use a USB stick method? how do I transfer copied ISO files from USB stick to the console? would getting a salvaged hard drive to work with the console worth hesitating or sticking to the original used one is good enough? finally would ISOs from The Vault here work fine if transferred to the console?