2. no flashing necessary.
3. it is really just plug and play if installing as a dx, if you go the zero route its still pretty much just as easy you just hafta make sure its pressed on there nice n tight so it dont pop off. really easy. opening the wii is easy, just make sure you apply firm pressure when loosening screws they will strip easily.
4. if your making your own 1:1 game backups you shouldnt have a problem with anything. im not sure anything is future proof, but i feel it will be good for a long time.
5. still not sure if i can post site links, will pm ya.
since you have an older wii you have the option of using the wasabi dx as a wasabi zero. i would recommend getting the clip with it and use it as a zero that way you benefit from 6x read speed and gamecube streaming. read up and do studying on it so you know what its all about. as of right now i would say the wasabi dx is the best chip out there, especially when used as a zero.