So I am a noob to wii modding scene. I have a US NTSC Wii with D2CKey and fw 3.4U.

All backup game dvds work fine (even SMG) except I tried Sonic & the Black knight and it asked me to update and warned that update might ruin my hw changes. so not knowing anything about updates I stopped.

Poked around this forum and I am very confused as to where to start.
Here's what I want:
Update fw 3.4u to 4.x and still be able to play all backups
Add USB loader so I can dump my iso files to an external Hard drive and play games off of it.
Add the ability to play MP4/MKV/XviD/AVI videos from USB HD
Add homebrew and/or wad manager so I can play those games via USB HD.

Can someone please tell me the steps I should take and versions of sofware/hacks I need to install to accomplish my wish list above without bricking my wii.

Thanks in advance.