Here is all I know:
1- You DO NOT need any exploits to run homebrew, but unless you configure it, you must put 1.5 homebrew in a GAME150 folder, and things like demos in a GAME303 folder. Devhook is not required to run an ISO, it can be launched from the XMB just like homebrew

2- What you have in the root directory depends on what homebrew you use, but usually there is an: ISO, PSP, and MP_ROOT folders, and if you see hidden items, a MEMSTICK.IND and a MSTK_PRO.IND

3- For the default settings, unless you used the advanced thing, everything is disabled and GAME folder is 3.03 homebrew by default


I hope this helped

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